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 <assert.h> 35#include <stdbool.h> 36#include <stdint.h> 37#include <stdio.h> 38#include <stdlib.h> 39#include <string.h> 40#include <unistd.h> 41#include <netinet/in.h> 42#include <openssl/err.h> 43#include <openssl/md5.h> 44#include <openssl/rand.h> 45 46#include "ctld.h" 47#include "iscsi_proto.h" 48 49static void login_send_error(struct pdu *request, 50 char class, char detail); 51 52static void 53login_set_nsg(struct pdu *response, int nsg) 54{ 55 struct iscsi_bhs_login_response *bhslr; 56 57 assert(nsg == BHSLR_STAGE_SECURITY_NEGOTIATION || 58 nsg == BHSLR_STAGE_OPERATIONAL_NEGOTIATION || 59 nsg == BHSLR_STAGE_FULL_FEATURE_PHASE); 60 61 bhslr = (struct iscsi_bhs_login_response *)response->pdu_bhs; 62 63 bhslr->bhslr_flags &= 0xFC; 64 bhslr->bhslr_flags |= nsg; 65} 66 67static int 68login_csg(const struct pdu *request) 69{ 70 struct iscsi_bhs_login_request *bhslr; 71 72 bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs; 73 74 return ((bhslr->bhslr_flags & 0x0C) >> 2); 75} 76 77static void 78login_set_csg(struct pdu *response, int csg) 79{ 80 struct iscsi_bhs_login_response *bhslr; 81 82 assert(csg == BHSLR_STAGE_SECURITY_NEGOTIATION || 83 csg == BHSLR_STAGE_OPERATIONAL_NEGOTIATION || 84 csg == BHSLR_STAGE_FULL_FEATURE_PHASE); 85 86 bhslr = (struct iscsi_bhs_login_response *)response->pdu_bhs; 87 88 bhslr->bhslr_flags &= 0xF3; 89 bhslr->bhslr_flags |= csg << 2; 90} 91 92static struct pdu * 93login_receive(struct connection *conn, bool initial) 94{ 95 struct pdu *request; 96 struct iscsi_bhs_login_request *bhslr; 97 98 request = pdu_new(conn); 99 pdu_receive(request); 100 if ((request->pdu_bhs->bhs_opcode & ~ISCSI_BHS_OPCODE_IMMEDIATE) != 101 ISCSI_BHS_OPCODE_LOGIN_REQUEST) { 102 /* 103 * The first PDU in session is special - if we receive any PDU 104 * different than login request, we have to drop the connection 105 * without sending response ("A target receiving any PDU 106 * except a Login request before the Login Phase is started MUST 107 * immediately terminate the connection on which the PDU 108 * was received.") 109 */ 110 if (initial == false) 111 login_send_error(request, 0x02, 0x0b); 112 log_errx(1, "protocol error: received invalid opcode 0x%x", 113 request->pdu_bhs->bhs_opcode); 114 } 115 bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs; 116 /* 117 * XXX: Implement the C flag some day. 118 */ 119 if ((bhslr->bhslr_flags & BHSLR_FLAGS_CONTINUE) != 0) { 120 login_send_error(request, 0x03, 0x00); 121 log_errx(1, "received Login PDU with unsupported \"C\" flag"); 122 } 123 if (bhslr->bhslr_version_max != 0x00) { 124 login_send_error(request, 0x02, 0x05); 125 log_errx(1, "received Login PDU with unsupported " 126 "Version-max 0x%x", bhslr->bhslr_version_max); 127 } 128 if (bhslr->bhslr_version_min != 0x00) { 129 login_send_error(request, 0x02, 0x05); 130 log_errx(1, "received Login PDU with unsupported " 131 "Version-min 0x%x", bhslr->bhslr_version_min); 132 } 133 if (ntohl(bhslr->bhslr_cmdsn) < conn->conn_cmdsn) { 134 login_send_error(request, 0x02, 0x05); 135 log_errx(1, "received Login PDU with decreasing CmdSN: " 136 "was %d, is %d", conn->conn_cmdsn, 137 ntohl(bhslr->bhslr_cmdsn)); 138 } 139 if (initial == false && 140 ntohl(bhslr->bhslr_expstatsn) != conn->conn_statsn) { 141 login_send_error(request, 0x02, 0x05); 142 log_errx(1, "received Login PDU with wrong ExpStatSN: " 143 "is %d, should be %d", ntohl(bhslr->bhslr_expstatsn), 144 conn->conn_statsn); 145 } 146 conn->conn_cmdsn = ntohl(bhslr->bhslr_cmdsn); 147 148 return (request); 149} 150 151static struct pdu * 152login_new_response(struct pdu *request) 153{ 154 struct pdu *response; 155 struct connection *conn; 156 struct iscsi_bhs_login_request *bhslr; 157 struct iscsi_bhs_login_response *bhslr2; 158 159 bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs; 160 conn = request->pdu_connection; 161 162 response = pdu_new_response(request); 163 bhslr2 = (struct iscsi_bhs_login_response *)response->pdu_bhs; 164 bhslr2->bhslr_opcode = ISCSI_BHS_OPCODE_LOGIN_RESPONSE; 165 login_set_csg(response, BHSLR_STAGE_SECURITY_NEGOTIATION); 166 memcpy(bhslr2->bhslr_isid, 167 bhslr->bhslr_isid, sizeof(bhslr2->bhslr_isid)); 168 bhslr2->bhslr_initiator_task_tag = bhslr->bhslr_initiator_task_tag; 169 bhslr2->bhslr_statsn = htonl(conn->conn_statsn++); 170 bhslr2->bhslr_expcmdsn = htonl(conn->conn_cmdsn); 171 bhslr2->bhslr_maxcmdsn = htonl(conn->conn_cmdsn); 172 173 return (response); 174} 175 176static void 177login_send_error(struct pdu *request, char class, char detail) 178{ 179 struct pdu *response; 180 struct iscsi_bhs_login_response *bhslr2; 181 182 log_debugx("sending Login Response PDU with failure class 0x%x/0x%x; " 183 "see next line for reason", class, detail); 184 response = login_new_response(request); 185 bhslr2 = (struct iscsi_bhs_login_response *)response->pdu_bhs; 186 bhslr2->bhslr_status_class = class; 187 bhslr2->bhslr_status_detail = detail; 188 189 pdu_send(response); 190 pdu_delete(response); 191} 192 193static int 194login_list_contains(const char *list, const char *what) 195{ 196 char *tofree, *str, *token; 197 198 tofree = str = checked_strdup(list); 199 200 while ((token = strsep(&str, ",")) != NULL) { 201 if (strcmp(token, what) == 0) { 202 free(tofree); 203 return (1); 204 } 205 } 206 free(tofree); 207 return (0); 208} 209 210static int 211login_list_prefers(const char *list, 212 const char *choice1, const char *choice2) 213{ 214 char *tofree, *str, *token; 215 216 tofree = str = checked_strdup(list); 217 218 while ((token = strsep(&str, ",")) != NULL) { 219 if (strcmp(token, choice1) == 0) { 220 free(tofree); 221 return (1); 222 } 223 if (strcmp(token, choice2) == 0) { 224 free(tofree); 225 return (2); 226 } 227 } 228 free(tofree); 229 return (-1); 230} 231 232static int 233login_hex2int(const char hex) 234{ 235 switch (hex) { 236 case '0': 237 return (0x00); 238 case '1': 239 return (0x01); 240 case '2': 241 return (0x02); 242 case '3': 243 return (0x03); 244 case '4': 245 return (0x04); 246 case '5': 247 return (0x05); 248 case '6': 249 return (0x06); 250 case '7': 251 return (0x07); 252 case '8': 253 return (0x08); 254 case '9': 255 return (0x09); 256 case 'a': 257 case 'A': 258 return (0x0a); 259 case 'b': 260 case 'B': 261 return (0x0b); 262 case 'c': 263 case 'C': 264 return (0x0c); 265 case 'd': 266 case 'D': 267 return (0x0d); 268 case 'e': 269 case 'E': 270 return (0x0e); 271 case 'f': 272 case 'F': 273 return (0x0f); 274 default: 275 return (-1); 276 } 277} 278 279/* 280 * XXX: Review this _carefully_. 281 */ 282static int 283login_hex2bin(const char *hex, char **binp, size_t *bin_lenp) 284{ 285 int i, hex_len, nibble; 286 bool lo = true; /* As opposed to 'hi'. */ 287 char *bin; 288 size_t bin_off, bin_len; 289 290 if (strncasecmp(hex, "0x", strlen("0x")) != 0) { 291 log_warnx("malformed variable, should start with \"0x\""); 292 return (-1); 293 } 294 295 hex += strlen("0x"); 296 hex_len = strlen(hex); 297 if (hex_len < 1) { 298 log_warnx("malformed variable; doesn't contain anything " 299 "but \"0x\""); 300 return (-1); 301 } 302 303 bin_len = hex_len / 2 + hex_len % 2; 304 bin = calloc(bin_len, 1); 305 if (bin == NULL) 306 log_err(1, "calloc"); 307 308 bin_off = bin_len - 1; 309 for (i = hex_len - 1; i >= 0; i--) { 310 nibble = login_hex2int(hex[i]); 311 if (nibble < 0) { 312 log_warnx("malformed variable, invalid char \"%c\"", 313 hex[i]); 314 return (-1); 315 } 316 317 assert(bin_off < bin_len); 318 if (lo) { 319 bin[bin_off] = nibble; 320 lo = false; 321 } else { 322 bin[bin_off] |= nibble << 4; 323 bin_off--; 324 lo = true; 325 } 326 } 327 328 *binp = bin; 329 *bin_lenp = bin_len; 330 return (0); 331} 332 333static char * 334login_bin2hex(const char *bin, size_t bin_len) 335{ 336 unsigned char *hex, *tmp, ch; 337 size_t hex_len; 338 size_t i; 339 340 hex_len = bin_len * 2 + 3; /* +2 for "0x", +1 for '\0'. */ 341 hex = malloc(hex_len); 342 if (hex == NULL) 343 log_err(1, "malloc"); 344 345 tmp = hex; 346 tmp += sprintf(tmp, "0x"); 347 for (i = 0; i < bin_len; i++) { 348 ch = bin[i]; 349 tmp += sprintf(tmp, "%02x", ch); 350 } 351 352 return (hex); 353} 354 355static void 356login_compute_md5(const char id, const char *secret, 357 const void *challenge, size_t challenge_len, void *response, 358 size_t response_len) 359{ 360 MD5_CTX ctx; 361 int rv; 362 363 assert(response_len == MD5_DIGEST_LENGTH); 364 365 MD5_Init(&ctx); 366 MD5_Update(&ctx, &id, sizeof(id)); 367 MD5_Update(&ctx, secret, strlen(secret)); 368 MD5_Update(&ctx, challenge, challenge_len); 369 rv = MD5_Final(response, &ctx); 370 if (rv != 1) 371 log_errx(1, "MD5_Final"); 372} 373 374#define LOGIN_CHALLENGE_LEN 1024 375 376static struct pdu * 377login_receive_chap_a(struct connection *conn) 378{ 379 struct pdu *request; 380 struct keys *request_keys; 381 const char *chap_a; 382 383 request = login_receive(conn, false); 384 request_keys = keys_new(); 385 keys_load(request_keys, request); 386 387 chap_a = keys_find(request_keys, "CHAP_A"); 388 if (chap_a == NULL) { 389 login_send_error(request, 0x02, 0x07); 390 log_errx(1, "received CHAP Login PDU without CHAP_A"); 391 } 392 if (login_list_contains(chap_a, "5") == 0) { 393 login_send_error(request, 0x02, 0x01); 394 log_errx(1, "received CHAP Login PDU with unsupported CHAP_A " 395 "\"%s\"", chap_a); 396 } 397 keys_delete(request_keys); 398 399 return (request); 400} 401 402static void 403login_send_chap_c(struct pdu *request, const unsigned char id, 404 const void *challenge, const size_t challenge_len) 405{ 406 struct pdu *response; 407 struct keys *response_keys; 408 char *chap_c, chap_i[4]; 409 410 chap_c = login_bin2hex(challenge, challenge_len); 411 snprintf(chap_i, sizeof(chap_i), "%d", id); 412 413 response = login_new_response(request); 414 response_keys = keys_new(); 415 keys_add(response_keys, "CHAP_A", "5"); 416 keys_add(response_keys, "CHAP_I", chap_i); 417 keys_add(response_keys, "CHAP_C", chap_c); 418 free(chap_c); 419 keys_save(response_keys, response); 420 pdu_send(response); 421 pdu_delete(response); 422 keys_delete(response_keys); 423} 424 425static struct pdu * 426login_receive_chap_r(struct connection *conn, 427 struct auth_group *ag, const unsigned char id, const void *challenge, 428 const size_t challenge_len, const struct auth **cap) 429{ 430 struct pdu *request; 431 struct keys *request_keys; 432 const char *chap_n, *chap_r; 433 char *response_bin, expected_response_bin[MD5_DIGEST_LENGTH]; 434 size_t response_bin_len; 435 const struct auth *auth; 436 int error; 437 438 request = login_receive(conn, false); 439 request_keys = keys_new(); 440 keys_load(request_keys, request); 441 442 chap_n = keys_find(request_keys, "CHAP_N"); 443 if (chap_n == NULL) { 444 login_send_error(request, 0x02, 0x07); 445 log_errx(1, "received CHAP Login PDU without CHAP_N"); 446 } 447 chap_r = keys_find(request_keys, "CHAP_R"); 448 if (chap_r == NULL) { 449 login_send_error(request, 0x02, 0x07); 450 log_errx(1, "received CHAP Login PDU without CHAP_R"); 451 } 452 error = login_hex2bin(chap_r, &response_bin, &response_bin_len); 453 if (error != 0) { 454 login_send_error(request, 0x02, 0x07); 455 log_errx(1, "received CHAP Login PDU with malformed CHAP_R"); 456 } 457 458 /* 459 * Verify the response. 460 */ 461 assert(ag->ag_type == AG_TYPE_CHAP || 462 ag->ag_type == AG_TYPE_CHAP_MUTUAL); 463 auth = auth_find(ag, chap_n); 464 if (auth == NULL) { 465 login_send_error(request, 0x02, 0x01); 466 log_errx(1, "received CHAP Login with invalid user \"%s\"", 467 chap_n); 468 } 469 470 assert(auth->a_secret != NULL); 471 assert(strlen(auth->a_secret) > 0); 472 login_compute_md5(id, auth->a_secret, challenge, 473 challenge_len, expected_response_bin, 474 sizeof(expected_response_bin)); 475 476 if (memcmp(response_bin, expected_response_bin, 477 sizeof(expected_response_bin)) != 0) { 478 login_send_error(request, 0x02, 0x01); 479 log_errx(1, "CHAP authentication failed for user \"%s\"", 480 auth->a_user); 481 } 482 483 keys_delete(request_keys); 484 free(response_bin); 485 486 *cap = auth; 487 return (request); 488} 489 490static void 491login_send_chap_success(struct pdu *request, 492 const struct auth *auth) 493{ 494 struct pdu *response; 495 struct keys *request_keys, *response_keys; 496 struct iscsi_bhs_login_response *bhslr2; 497 const char *chap_i, *chap_c; 498 char *chap_r, *challenge, response_bin[MD5_DIGEST_LENGTH]; 499 size_t challenge_len; 500 unsigned char id; 501 int error; 502 503 response = login_new_response(request); 504 bhslr2 = (struct iscsi_bhs_login_response *)response->pdu_bhs; 505 bhslr2->bhslr_flags |= BHSLR_FLAGS_TRANSIT; 506 login_set_nsg(response, BHSLR_STAGE_OPERATIONAL_NEGOTIATION); 507 508 /* 509 * Actually, one more thing: mutual authentication. 510 */ 511 request_keys = keys_new(); 512 keys_load(request_keys, request); 513 chap_i = keys_find(request_keys, "CHAP_I"); 514 chap_c = keys_find(request_keys, "CHAP_C"); 515 if (chap_i != NULL || chap_c != NULL) { 516 if (chap_i == NULL) { 517 login_send_error(request, 0x02, 0x07); 518 log_errx(1, "initiator requested target " 519 "authentication, but didn't send CHAP_I"); 520 } 521 if (chap_c == NULL) { 522 login_send_error(request, 0x02, 0x07); 523 log_errx(1, "initiator requested target " 524 "authentication, but didn't send CHAP_C"); 525 } 526 if (auth->a_auth_group->ag_type != AG_TYPE_CHAP_MUTUAL) { 527 login_send_error(request, 0x02, 0x01); 528 log_errx(1, "initiator requests target authentication " 529 "for user \"%s\", but mutual user/secret " 530 "is not set", auth->a_user); 531 } 532 533 id = strtoul(chap_i, NULL, 10); 534 error = login_hex2bin(chap_c, &challenge, &challenge_len); 535 if (error != 0) { 536 login_send_error(request, 0x02, 0x07); 537 log_errx(1, "received CHAP Login PDU with malformed " 538 "CHAP_C"); 539 } 540 541 log_debugx("performing mutual authentication as user \"%s\"", 542 auth->a_mutual_user); 543 login_compute_md5(id, auth->a_mutual_secret, challenge, 544 challenge_len, response_bin, sizeof(response_bin)); 545 546 chap_r = login_bin2hex(response_bin, 547 sizeof(response_bin)); 548 response_keys = keys_new(); 549 keys_add(response_keys, "CHAP_N", auth->a_mutual_user); 550 keys_add(response_keys, "CHAP_R", chap_r); 551 free(chap_r); 552 keys_save(response_keys, response); 553 keys_delete(response_keys); 554 } else { 555 log_debugx("initiator did not request target authentication"); 556 } 557 558 keys_delete(request_keys); 559 pdu_send(response); 560 pdu_delete(response); 561} 562 563static void 564login_chap(struct connection *conn, struct auth_group *ag) 565{ 566 const struct auth *auth; 567 struct pdu *request; 568 char challenge_bin[LOGIN_CHALLENGE_LEN]; 569 unsigned char id; 570 int rv; 571 572 /* 573 * Receive CHAP_A PDU. 574 */ 575 log_debugx("beginning CHAP authentication; waiting for CHAP_A"); 576 request = login_receive_chap_a(conn); 577 578 /* 579 * Generate the challenge. 580 */ 581 rv = RAND_bytes(challenge_bin, sizeof(challenge_bin)); 582 if (rv != 1) { 583 login_send_error(request, 0x03, 0x02); 584 log_errx(1, "RAND_bytes failed: %s", 585 ERR_error_string(ERR_get_error(), NULL)); 586 } 587 rv = RAND_bytes(&id, sizeof(id)); 588 if (rv != 1) { 589 login_send_error(request, 0x03, 0x02); 590 log_errx(1, "RAND_bytes failed: %s", 591 ERR_error_string(ERR_get_error(), NULL)); 592 } 593 594 /* 595 * Send the challenge. 596 */ 597 log_debugx("sending CHAP_C, binary challenge size is %zd bytes", 598 sizeof(challenge_bin)); 599 login_send_chap_c(request, id, challenge_bin, 600 sizeof(challenge_bin)); 601 pdu_delete(request); 602 603 /* 604 * Receive CHAP_N/CHAP_R PDU and authenticate. 605 */ 606 log_debugx("waiting for CHAP_N/CHAP_R"); 607 request = login_receive_chap_r(conn, ag, id, challenge_bin, 608 sizeof(challenge_bin), &auth); 609 610 /* 611 * Yay, authentication succeeded! 612 */ 613 log_debugx("authentication succeeded for user \"%s\"; " 614 "transitioning to Negotiation Phase", auth->a_user); 615 login_send_chap_success(request, auth); 616 pdu_delete(request); 617} 618 619static void 620login_negotiate_key(struct pdu *request, const char *name, 621 const char *value, bool skipped_security, struct keys *response_keys) 622{ 623 int which, tmp; 624 struct connection *conn; 625 626 conn = request->pdu_connection; 627 628 if (strcmp(name, "InitiatorName") == 0) { 629 if (!skipped_security) 630 log_errx(1, "initiator resent InitiatorName"); 631 } else if (strcmp(name, "SessionType") == 0) { 632 if (!skipped_security) 633 log_errx(1, "initiator resent SessionType"); 634 } else if (strcmp(name, "TargetName") == 0) { 635 if (!skipped_security) 636 log_errx(1, "initiator resent TargetName"); 637 } else if (strcmp(name, "InitiatorAlias") == 0) { 638 if (conn->conn_initiator_alias != NULL) 639 free(conn->conn_initiator_alias); 640 conn->conn_initiator_alias = checked_strdup(value); 641 } else if (strcmp(value, "Irrelevant") == 0) { 642 /* Ignore. */ 643 } else if (strcmp(name, "HeaderDigest") == 0) { 644 /* 645 * We don't handle digests for discovery sessions. 646 */ 647 if (conn->conn_session_type == CONN_SESSION_TYPE_DISCOVERY) { 648 log_debugx("discovery session; digests disabled"); 649 keys_add(response_keys, name, "None"); 650 return; 651 } 652 653 which = login_list_prefers(value, "CRC32C", "None"); 654 switch (which) { 655 case 1: 656 log_debugx("initiator prefers CRC32C " 657 "for header digest; we'll use it"); 658 conn->conn_header_digest = CONN_DIGEST_CRC32C; 659 keys_add(response_keys, name, "CRC32C"); 660 break; 661 case 2: 662 log_debugx("initiator prefers not to do " 663 "header digest; we'll comply"); 664 keys_add(response_keys, name, "None"); 665 break; 666 default: 667 log_warnx("initiator sent unrecognized " 668 "HeaderDigest value \"%s\"; will use None", value); 669 keys_add(response_keys, name, "None"); 670 break; 671 } 672 } else if (strcmp(name, "DataDigest") == 0) { 673 if (conn->conn_session_type == CONN_SESSION_TYPE_DISCOVERY) { 674 log_debugx("discovery session; digests disabled"); 675 keys_add(response_keys, name, "None"); 676 return; 677 } 678 679 which = login_list_prefers(value, "CRC32C", "None"); 680 switch (which) { 681 case 1: 682 log_debugx("initiator prefers CRC32C " 683 "for data digest; we'll use it"); 684 conn->conn_data_digest = CONN_DIGEST_CRC32C; 685 keys_add(response_keys, name, "CRC32C"); 686 break; 687 case 2: 688 log_debugx("initiator prefers not to do " 689 "data digest; we'll comply"); 690 keys_add(response_keys, name, "None"); 691 break; 692 default: 693 log_warnx("initiator sent unrecognized " 694 "DataDigest value \"%s\"; will use None", value); 695 keys_add(response_keys, name, "None"); 696 break; 697 } 698 } else if (strcmp(name, "MaxConnections") == 0) { 699 keys_add(response_keys, name, "1"); 700 } else if (strcmp(name, "InitialR2T") == 0) { 701 keys_add(response_keys, name, "Yes"); 702 } else if (strcmp(name, "ImmediateData") == 0) { 703 if (conn->conn_session_type == CONN_SESSION_TYPE_DISCOVERY) { 704 log_debugx("discovery session; ImmediateData irrelevant"); 705 keys_add(response_keys, name, "Irrelevant"); 706 } else { 707 if (strcmp(value, "Yes") == 0) { 708 conn->conn_immediate_data = true; 709 keys_add(response_keys, name, "Yes"); 710 } else { 711 conn->conn_immediate_data = false; 712 keys_add(response_keys, name, "No"); 713 } 714 } 715 } else if (strcmp(name, "MaxRecvDataSegmentLength") == 0) { 716 tmp = strtoul(value, NULL, 10); 717 if (tmp <= 0) { 718 login_send_error(request, 0x02, 0x00); 719 log_errx(1, "received invalid " 720 "MaxRecvDataSegmentLength"); 721 } 722 if (tmp > MAX_DATA_SEGMENT_LENGTH) { 723 log_debugx("capping MaxRecvDataSegmentLength " 724 "from %d to %d", tmp, MAX_DATA_SEGMENT_LENGTH); 725 tmp = MAX_DATA_SEGMENT_LENGTH; 726 } 727 conn->conn_max_data_segment_length = tmp; 728 keys_add_int(response_keys, name, tmp); 729 } else if (strcmp(name, "MaxBurstLength") == 0) { 730 tmp = strtoul(value, NULL, 10); 731 if (tmp <= 0) { 732 login_send_error(request, 0x02, 0x00); 733 log_errx(1, "received invalid MaxBurstLength"); 734 } 735 if (tmp > MAX_BURST_LENGTH) { 736 log_debugx("capping MaxBurstLength from %d to %d", 737 tmp, MAX_BURST_LENGTH); 738 tmp = MAX_BURST_LENGTH; 739 } 740 conn->conn_max_burst_length = tmp; 741 keys_add(response_keys, name, value); 742 } else if (strcmp(name, "FirstBurstLength") == 0) { 743 tmp = strtoul(value, NULL, 10); 744 if (tmp <= 0) { 745 login_send_error(request, 0x02, 0x00); 746 log_errx(1, "received invalid " 747 "FirstBurstLength"); 748 } 749 if (tmp > MAX_DATA_SEGMENT_LENGTH) { 750 log_debugx("capping FirstBurstLength from %d to %d", 751 tmp, MAX_DATA_SEGMENT_LENGTH); 752 tmp = MAX_DATA_SEGMENT_LENGTH; 753 } 754 /* 755 * We don't pass the value to the kernel; it only enforces 756 * hardcoded limit anyway. 757 */ 758 keys_add_int(response_keys, name, tmp); 759 } else if (strcmp(name, "DefaultTime2Wait") == 0) { 760 keys_add(response_keys, name, value); 761 } else if (strcmp(name, "DefaultTime2Retain") == 0) { 762 keys_add(response_keys, name, "0"); 763 } else if (strcmp(name, "MaxOutstandingR2T") == 0) { 764 keys_add(response_keys, name, "1"); 765 } else if (strcmp(name, "DataPDUInOrder") == 0) { 766 keys_add(response_keys, name, "Yes"); 767 } else if (strcmp(name, "DataSequenceInOrder") == 0) { 768 keys_add(response_keys, name, "Yes"); 769 } else if (strcmp(name, "ErrorRecoveryLevel") == 0) { 770 keys_add(response_keys, name, "0"); 771 } else if (strcmp(name, "OFMarker") == 0) { 772 keys_add(response_keys, name, "No"); 773 } else if (strcmp(name, "IFMarker") == 0) { 774 keys_add(response_keys, name, "No"); 775 } else { 776 log_debugx("unknown key \"%s\"; responding " 777 "with NotUnderstood", name); 778 keys_add(response_keys, name, "NotUnderstood"); 779 } 780} 781 782static void 783login_negotiate(struct connection *conn, struct pdu *request) 784{ 785 struct pdu *response; 786 struct iscsi_bhs_login_response *bhslr2; 787 struct keys *request_keys, *response_keys; 788 char *portal_group_tag; 789 int i, rv; 790 bool skipped_security; 791 792 if (request == NULL) { 793 log_debugx("beginning operational parameter negotiation; " 794 "waiting for Login PDU"); 795 request = login_receive(conn, false); 796 skipped_security = false; 797 } else 798 skipped_security = true; 799 800 request_keys = keys_new(); 801 keys_load(request_keys, request); 802 803 response = login_new_response(request); 804 bhslr2 = (struct iscsi_bhs_login_response *)response->pdu_bhs; 805 bhslr2->bhslr_flags |= BHSLR_FLAGS_TRANSIT; 806 bhslr2->bhslr_tsih = htons(0xbadd); 807 login_set_csg(response, BHSLR_STAGE_OPERATIONAL_NEGOTIATION); 808 login_set_nsg(response, BHSLR_STAGE_FULL_FEATURE_PHASE); 809 response_keys = keys_new(); 810 811 if (skipped_security && 812 conn->conn_session_type == CONN_SESSION_TYPE_NORMAL) { 813 if (conn->conn_target->t_alias != NULL) 814 keys_add(response_keys, 815 "TargetAlias", conn->conn_target->t_alias); 816 rv = asprintf(&portal_group_tag, "%d", 817 conn->conn_portal->p_portal_group->pg_tag); 818 if (rv <= 0) 819 log_err(1, "asprintf"); 820 keys_add(response_keys, 821 "TargetPortalGroupTag", portal_group_tag); 822 free(portal_group_tag); 823 } 824 825 for (i = 0; i < KEYS_MAX; i++) { 826 if (request_keys->keys_names[i] == NULL) 827 break; 828 829 login_negotiate_key(request, request_keys->keys_names[i], 830 request_keys->keys_values[i], skipped_security, 831 response_keys); 832 } 833 834 log_debugx("operational parameter negotiation done; " 835 "transitioning to Full Feature Phase"); 836 837 keys_save(response_keys, response); 838 pdu_send(response); 839 pdu_delete(response); 840 keys_delete(response_keys); 841 pdu_delete(request); 842 keys_delete(request_keys); 843} 844 845void 846login(struct connection *conn) 847{ 848 struct pdu *request, *response; 849 struct iscsi_bhs_login_request *bhslr; 850 struct iscsi_bhs_login_response *bhslr2; 851 struct keys *request_keys, *response_keys; 852 struct auth_group *ag; 853 const char *initiator_name, *initiator_alias, *session_type, 854 *target_name, *auth_method; 855 char *portal_group_tag; 856 int rv; 857 858 /* 859 * Handle the initial Login Request - figure out required authentication 860 * method and either transition to the next phase, if no authentication 861 * is required, or call appropriate authentication code. 862 */ 863 log_debugx("beginning Login Phase; waiting for Login PDU"); 864 request = login_receive(conn, true); 865 bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs; 866 if (bhslr->bhslr_tsih != 0) { 867 login_send_error(request, 0x02, 0x0a); 868 log_errx(1, "received Login PDU with non-zero TSIH"); 869 } 870 871 memcpy(conn->conn_initiator_isid, bhslr->bhslr_isid, 872 sizeof(conn->conn_initiator_isid)); 873 874 /* 875 * XXX: Implement the C flag some day. 876 */ 877 request_keys = keys_new(); 878 keys_load(request_keys, request); 879 880 assert(conn->conn_initiator_name == NULL); 881 initiator_name = keys_find(request_keys, "InitiatorName"); 882 if (initiator_name == NULL) { 883 login_send_error(request, 0x02, 0x07); 884 log_errx(1, "received Login PDU without InitiatorName"); 885 } 886 if (valid_iscsi_name(initiator_name) == false) { 887 login_send_error(request, 0x02, 0x00); 888 log_errx(1, "received Login PDU with invalid InitiatorName"); 889 } 890 conn->conn_initiator_name = checked_strdup(initiator_name); 891 log_set_peer_name(conn->conn_initiator_name); 892 /* 893 * XXX: This doesn't work (does nothing) because of Capsicum. 894 */ 895 setproctitle("%s (%s)", conn->conn_initiator_addr, conn->conn_initiator_name); 896 897 initiator_alias = keys_find(request_keys, "InitiatorAlias"); 898 if (initiator_alias != NULL) 899 conn->conn_initiator_alias = checked_strdup(initiator_alias); 900 901 assert(conn->conn_session_type == CONN_SESSION_TYPE_NONE); 902 session_type = keys_find(request_keys, "SessionType"); 903 if (session_type != NULL) { 904 if (strcmp(session_type, "Normal") == 0) { 905 conn->conn_session_type = CONN_SESSION_TYPE_NORMAL; 906 } else if (strcmp(session_type, "Discovery") == 0) { 907 conn->conn_session_type = CONN_SESSION_TYPE_DISCOVERY; 908 } else { 909 login_send_error(request, 0x02, 0x00); 910 log_errx(1, "received Login PDU with invalid " 911 "SessionType \"%s\"", session_type); 912 } 913 } else 914 conn->conn_session_type = CONN_SESSION_TYPE_NORMAL; 915 916 assert(conn->conn_target == NULL); 917 if (conn->conn_session_type == CONN_SESSION_TYPE_NORMAL) { 918 target_name = keys_find(request_keys, "TargetName"); 919 if (target_name == NULL) { 920 login_send_error(request, 0x02, 0x07); 921 log_errx(1, "received Login PDU without TargetName"); 922 } 923 924 conn->conn_target = 925 target_find(conn->conn_portal->p_portal_group->pg_conf, 926 target_name); 927 if (conn->conn_target == NULL) { 928 login_send_error(request, 0x02, 0x03); 929 log_errx(1, "requested target \"%s\" not found", 930 target_name); 931 } 932 } 933 934 /* 935 * At this point we know what kind of authentication we need. 936 */ 937 if (conn->conn_session_type == CONN_SESSION_TYPE_NORMAL) { 938 ag = conn->conn_target->t_auth_group; 939 if (ag->ag_name != NULL) { 940 log_debugx("initiator requests to connect " 941 "to target \"%s\"; auth-group \"%s\"", 942 conn->conn_target->t_name, 943 conn->conn_target->t_auth_group->ag_name); 944 } else { 945 log_debugx("initiator requests to connect " 946 "to target \"%s\"", conn->conn_target->t_name); 947 } 948 } else { 949 assert(conn->conn_session_type == CONN_SESSION_TYPE_DISCOVERY); 950 ag = conn->conn_portal->p_portal_group->pg_discovery_auth_group; 951 if (ag->ag_name != NULL) { 952 log_debugx("initiator requests " 953 "discovery session; auth-group \"%s\"", ag->ag_name); 954 } else { 955 log_debugx("initiator requests discovery session"); 956 } 957 } 958 959 /* 960 * Enforce initiator-name and initiator-portal. 961 */ 962 if (auth_name_defined(ag)) { 963 if (auth_name_find(ag, initiator_name) == NULL) { 964 login_send_error(request, 0x02, 0x02); 965 log_errx(1, "initiator does not match allowed " 966 "initiator names"); 967 } 968 log_debugx("initiator matches allowed initiator names"); 969 } else { 970 log_debugx("auth-group does not define initiator name " 971 "restrictions"); 972 } 973 974 if (auth_portal_defined(ag)) { 975 if (auth_portal_find(ag, &conn->conn_initiator_sa) == NULL) { 976 login_send_error(request, 0x02, 0x02); 977 log_errx(1, "initiator does not match allowed " 978 "initiator portals"); 979 } 980 log_debugx("initiator matches allowed initiator portals"); 981 } else { 982 log_debugx("auth-group does not define initiator portal " 983 "restrictions"); 984 } 985 986 /* 987 * Let's see if the initiator intends to do any kind of authentication 988 * at all. 989 */ 990 if (login_csg(request) == BHSLR_STAGE_OPERATIONAL_NEGOTIATION) { 991 if (ag->ag_type != AG_TYPE_NO_AUTHENTICATION) { 992 login_send_error(request, 0x02, 0x01); 993 log_errx(1, "initiator skipped the authentication, " 994 "but authentication is required"); 995 } 996 997 keys_delete(request_keys); 998 999 log_debugx("initiator skipped the authentication, " 1000 "and we don't need it; proceeding with negotiation"); 1001 login_negotiate(conn, request); 1002 return; 1003 } 1004 1005 if (ag->ag_type == AG_TYPE_NO_AUTHENTICATION) { 1006 /* 1007 * Initiator might want to to authenticate, 1008 * but we don't need it. 1009 */ 1010 log_debugx("authentication not required; " 1011 "transitioning to operational parameter negotiation"); 1012 1013 if ((bhslr->bhslr_flags & BHSLR_FLAGS_TRANSIT) == 0) 1014 log_warnx("initiator did not set the \"T\" flag; " 1015 "transitioning anyway"); 1016 1017 response = login_new_response(request); 1018 bhslr2 = (struct iscsi_bhs_login_response *)response->pdu_bhs; 1019 bhslr2->bhslr_flags |= BHSLR_FLAGS_TRANSIT; 1020 login_set_nsg(response, 1021 BHSLR_STAGE_OPERATIONAL_NEGOTIATION); 1022 response_keys = keys_new(); 1023 /* 1024 * Required by Linux initiator. 1025 */ 1026 auth_method = keys_find(request_keys, "AuthMethod"); 1027 if (auth_method != NULL && 1028 login_list_contains(auth_method, "None")) 1029 keys_add(response_keys, "AuthMethod", "None"); 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 rv = asprintf(&portal_group_tag, "%d", 1036 conn->conn_portal->p_portal_group->pg_tag); 1037 if (rv <= 0) 1038 log_err(1, "asprintf"); 1039 keys_add(response_keys, 1040 "TargetPortalGroupTag", portal_group_tag); 1041 free(portal_group_tag); 1042 } 1043 keys_save(response_keys, response); 1044 pdu_send(response); 1045 pdu_delete(response); 1046 keys_delete(response_keys); 1047 pdu_delete(request); 1048 keys_delete(request_keys); 1049 1050 login_negotiate(conn, NULL); 1051 return; 1052 } 1053 1054 if (ag->ag_type == AG_TYPE_DENY) { 1055 login_send_error(request, 0x02, 0x01); 1056 log_errx(1, "auth-type is \"deny\""); 1057 } 1058 1059 if (ag->ag_type == AG_TYPE_UNKNOWN) { 1060 /* 1061 * This can happen with empty auth-group. 1062 */ 1063 login_send_error(request, 0x02, 0x01); 1064 log_errx(1, "auth-type not set, denying access"); 1065 } 1066 1067 log_debugx("CHAP authentication required"); 1068 1069 auth_method = keys_find(request_keys, "AuthMethod"); 1070 if (auth_method == NULL) { 1071 login_send_error(request, 0x02, 0x07); 1072 log_errx(1, "received Login PDU without AuthMethod"); 1073 } 1074 /* 1075 * XXX: This should be Reject, not just a login failure (5.3.2). 1076 */ 1077 if (login_list_contains(auth_method, "CHAP") == 0) { 1078 login_send_error(request, 0x02, 0x01); 1079 log_errx(1, "initiator requests unsupported AuthMethod \"%s\" " 1080 "instead of \"CHAP\"", auth_method); 1081 } 1082 1083 response = login_new_response(request); 1084 1085 response_keys = keys_new(); 1086 keys_add(response_keys, "AuthMethod", "CHAP"); 1087 if (conn->conn_session_type == CONN_SESSION_TYPE_NORMAL) { 1088 if (conn->conn_target->t_alias != NULL) 1089 keys_add(response_keys, 1090 "TargetAlias", conn->conn_target->t_alias); 1091 rv = asprintf(&portal_group_tag, "%d", 1092 conn->conn_portal->p_portal_group->pg_tag); 1093 if (rv <= 0) 1094 log_err(1, "asprintf"); 1095 keys_add(response_keys, 1096 "TargetPortalGroupTag", portal_group_tag); 1097 free(portal_group_tag); 1098 } 1099 keys_save(response_keys, response); 1100 1101 pdu_send(response); 1102 pdu_delete(response); 1103 keys_delete(response_keys); 1104 pdu_delete(request); 1105 keys_delete(request_keys); 1106 1107 login_chap(conn, ag); 1108 1109 login_negotiate(conn, NULL); 1110} 1111