login.c revision 270137
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 * $FreeBSD: stable/10/usr.sbin/ctld/login.c 270137 2014-08-18 16:06:04Z mav $ 30 */ 31 32#include <assert.h> 33#include <stdbool.h> 34#include <stdint.h> 35#include <stdio.h> 36#include <stdlib.h> 37#include <string.h> 38#include <unistd.h> 39#include <netinet/in.h> 40#include <openssl/err.h> 41#include <openssl/md5.h> 42#include <openssl/rand.h> 43 44#include "ctld.h" 45#include "iscsi_proto.h" 46 47static void login_send_error(struct pdu *request, 48 char class, char detail); 49 50static void 51login_set_nsg(struct pdu *response, int nsg) 52{ 53 struct iscsi_bhs_login_response *bhslr; 54 55 assert(nsg == BHSLR_STAGE_SECURITY_NEGOTIATION || 56 nsg == BHSLR_STAGE_OPERATIONAL_NEGOTIATION || 57 nsg == BHSLR_STAGE_FULL_FEATURE_PHASE); 58 59 bhslr = (struct iscsi_bhs_login_response *)response->pdu_bhs; 60 61 bhslr->bhslr_flags &= 0xFC; 62 bhslr->bhslr_flags |= nsg; 63} 64 65static int 66login_csg(const struct pdu *request) 67{ 68 struct iscsi_bhs_login_request *bhslr; 69 70 bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs; 71 72 return ((bhslr->bhslr_flags & 0x0C) >> 2); 73} 74 75static void 76login_set_csg(struct pdu *response, int csg) 77{ 78 struct iscsi_bhs_login_response *bhslr; 79 80 assert(csg == BHSLR_STAGE_SECURITY_NEGOTIATION || 81 csg == BHSLR_STAGE_OPERATIONAL_NEGOTIATION || 82 csg == BHSLR_STAGE_FULL_FEATURE_PHASE); 83 84 bhslr = (struct iscsi_bhs_login_response *)response->pdu_bhs; 85 86 bhslr->bhslr_flags &= 0xF3; 87 bhslr->bhslr_flags |= csg << 2; 88} 89 90static struct pdu * 91login_receive(struct connection *conn, bool initial) 92{ 93 struct pdu *request; 94 struct iscsi_bhs_login_request *bhslr; 95 96 request = pdu_new(conn); 97 pdu_receive(request); 98 if ((request->pdu_bhs->bhs_opcode & ~ISCSI_BHS_OPCODE_IMMEDIATE) != 99 ISCSI_BHS_OPCODE_LOGIN_REQUEST) { 100 /* 101 * The first PDU in session is special - if we receive any PDU 102 * different than login request, we have to drop the connection 103 * without sending response ("A target receiving any PDU 104 * except a Login request before the Login Phase is started MUST 105 * immediately terminate the connection on which the PDU 106 * was received.") 107 */ 108 if (initial == false) 109 login_send_error(request, 0x02, 0x0b); 110 log_errx(1, "protocol error: received invalid opcode 0x%x", 111 request->pdu_bhs->bhs_opcode); 112 } 113 bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs; 114 /* 115 * XXX: Implement the C flag some day. 116 */ 117 if ((bhslr->bhslr_flags & BHSLR_FLAGS_CONTINUE) != 0) { 118 login_send_error(request, 0x03, 0x00); 119 log_errx(1, "received Login PDU with unsupported \"C\" flag"); 120 } 121 if (bhslr->bhslr_version_max != 0x00) { 122 login_send_error(request, 0x02, 0x05); 123 log_errx(1, "received Login PDU with unsupported " 124 "Version-max 0x%x", bhslr->bhslr_version_max); 125 } 126 if (bhslr->bhslr_version_min != 0x00) { 127 login_send_error(request, 0x02, 0x05); 128 log_errx(1, "received Login PDU with unsupported " 129 "Version-min 0x%x", bhslr->bhslr_version_min); 130 } 131 if (ntohl(bhslr->bhslr_cmdsn) < conn->conn_cmdsn) { 132 login_send_error(request, 0x02, 0x05); 133 log_errx(1, "received Login PDU with decreasing CmdSN: " 134 "was %d, is %d", conn->conn_cmdsn, 135 ntohl(bhslr->bhslr_cmdsn)); 136 } 137 if (initial == false && 138 ntohl(bhslr->bhslr_expstatsn) != conn->conn_statsn) { 139 login_send_error(request, 0x02, 0x05); 140 log_errx(1, "received Login PDU with wrong ExpStatSN: " 141 "is %d, should be %d", ntohl(bhslr->bhslr_expstatsn), 142 conn->conn_statsn); 143 } 144 conn->conn_cmdsn = ntohl(bhslr->bhslr_cmdsn); 145 146 return (request); 147} 148 149static struct pdu * 150login_new_response(struct pdu *request) 151{ 152 struct pdu *response; 153 struct connection *conn; 154 struct iscsi_bhs_login_request *bhslr; 155 struct iscsi_bhs_login_response *bhslr2; 156 157 bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs; 158 conn = request->pdu_connection; 159 160 response = pdu_new_response(request); 161 bhslr2 = (struct iscsi_bhs_login_response *)response->pdu_bhs; 162 bhslr2->bhslr_opcode = ISCSI_BHS_OPCODE_LOGIN_RESPONSE; 163 login_set_csg(response, BHSLR_STAGE_SECURITY_NEGOTIATION); 164 memcpy(bhslr2->bhslr_isid, 165 bhslr->bhslr_isid, sizeof(bhslr2->bhslr_isid)); 166 bhslr2->bhslr_initiator_task_tag = bhslr->bhslr_initiator_task_tag; 167 bhslr2->bhslr_statsn = htonl(conn->conn_statsn++); 168 bhslr2->bhslr_expcmdsn = htonl(conn->conn_cmdsn); 169 bhslr2->bhslr_maxcmdsn = htonl(conn->conn_cmdsn); 170 171 return (response); 172} 173 174static void 175login_send_error(struct pdu *request, char class, char detail) 176{ 177 struct pdu *response; 178 struct iscsi_bhs_login_response *bhslr2; 179 180 log_debugx("sending Login Response PDU with failure class 0x%x/0x%x; " 181 "see next line for reason", class, detail); 182 response = login_new_response(request); 183 bhslr2 = (struct iscsi_bhs_login_response *)response->pdu_bhs; 184 bhslr2->bhslr_status_class = class; 185 bhslr2->bhslr_status_detail = detail; 186 187 pdu_send(response); 188 pdu_delete(response); 189} 190 191static int 192login_list_contains(const char *list, const char *what) 193{ 194 char *tofree, *str, *token; 195 196 tofree = str = checked_strdup(list); 197 198 while ((token = strsep(&str, ",")) != NULL) { 199 if (strcmp(token, what) == 0) { 200 free(tofree); 201 return (1); 202 } 203 } 204 free(tofree); 205 return (0); 206} 207 208static int 209login_list_prefers(const char *list, 210 const char *choice1, const char *choice2) 211{ 212 char *tofree, *str, *token; 213 214 tofree = str = checked_strdup(list); 215 216 while ((token = strsep(&str, ",")) != NULL) { 217 if (strcmp(token, choice1) == 0) { 218 free(tofree); 219 return (1); 220 } 221 if (strcmp(token, choice2) == 0) { 222 free(tofree); 223 return (2); 224 } 225 } 226 free(tofree); 227 return (-1); 228} 229 230static int 231login_hex2int(const char hex) 232{ 233 switch (hex) { 234 case '0': 235 return (0x00); 236 case '1': 237 return (0x01); 238 case '2': 239 return (0x02); 240 case '3': 241 return (0x03); 242 case '4': 243 return (0x04); 244 case '5': 245 return (0x05); 246 case '6': 247 return (0x06); 248 case '7': 249 return (0x07); 250 case '8': 251 return (0x08); 252 case '9': 253 return (0x09); 254 case 'a': 255 case 'A': 256 return (0x0a); 257 case 'b': 258 case 'B': 259 return (0x0b); 260 case 'c': 261 case 'C': 262 return (0x0c); 263 case 'd': 264 case 'D': 265 return (0x0d); 266 case 'e': 267 case 'E': 268 return (0x0e); 269 case 'f': 270 case 'F': 271 return (0x0f); 272 default: 273 return (-1); 274 } 275} 276 277/* 278 * XXX: Review this _carefully_. 279 */ 280static int 281login_hex2bin(const char *hex, char **binp, size_t *bin_lenp) 282{ 283 int i, hex_len, nibble; 284 bool lo = true; /* As opposed to 'hi'. */ 285 char *bin; 286 size_t bin_off, bin_len; 287 288 if (strncasecmp(hex, "0x", strlen("0x")) != 0) { 289 log_warnx("malformed variable, should start with \"0x\""); 290 return (-1); 291 } 292 293 hex += strlen("0x"); 294 hex_len = strlen(hex); 295 if (hex_len < 1) { 296 log_warnx("malformed variable; doesn't contain anything " 297 "but \"0x\""); 298 return (-1); 299 } 300 301 bin_len = hex_len / 2 + hex_len % 2; 302 bin = calloc(bin_len, 1); 303 if (bin == NULL) 304 log_err(1, "calloc"); 305 306 bin_off = bin_len - 1; 307 for (i = hex_len - 1; i >= 0; i--) { 308 nibble = login_hex2int(hex[i]); 309 if (nibble < 0) { 310 log_warnx("malformed variable, invalid char \"%c\"", 311 hex[i]); 312 return (-1); 313 } 314 315 assert(bin_off < bin_len); 316 if (lo) { 317 bin[bin_off] = nibble; 318 lo = false; 319 } else { 320 bin[bin_off] |= nibble << 4; 321 bin_off--; 322 lo = true; 323 } 324 } 325 326 *binp = bin; 327 *bin_lenp = bin_len; 328 return (0); 329} 330 331static char * 332login_bin2hex(const char *bin, size_t bin_len) 333{ 334 unsigned char *hex, *tmp, ch; 335 size_t hex_len; 336 size_t i; 337 338 hex_len = bin_len * 2 + 3; /* +2 for "0x", +1 for '\0'. */ 339 hex = malloc(hex_len); 340 if (hex == NULL) 341 log_err(1, "malloc"); 342 343 tmp = hex; 344 tmp += sprintf(tmp, "0x"); 345 for (i = 0; i < bin_len; i++) { 346 ch = bin[i]; 347 tmp += sprintf(tmp, "%02x", ch); 348 } 349 350 return (hex); 351} 352 353static void 354login_compute_md5(const char id, const char *secret, 355 const void *challenge, size_t challenge_len, void *response, 356 size_t response_len) 357{ 358 MD5_CTX ctx; 359 int rv; 360 361 assert(response_len == MD5_DIGEST_LENGTH); 362 363 MD5_Init(&ctx); 364 MD5_Update(&ctx, &id, sizeof(id)); 365 MD5_Update(&ctx, secret, strlen(secret)); 366 MD5_Update(&ctx, challenge, challenge_len); 367 rv = MD5_Final(response, &ctx); 368 if (rv != 1) 369 log_errx(1, "MD5_Final"); 370} 371 372#define LOGIN_CHALLENGE_LEN 1024 373 374static struct pdu * 375login_receive_chap_a(struct connection *conn) 376{ 377 struct pdu *request; 378 struct keys *request_keys; 379 const char *chap_a; 380 381 request = login_receive(conn, false); 382 request_keys = keys_new(); 383 keys_load(request_keys, request); 384 385 chap_a = keys_find(request_keys, "CHAP_A"); 386 if (chap_a == NULL) { 387 login_send_error(request, 0x02, 0x07); 388 log_errx(1, "received CHAP Login PDU without CHAP_A"); 389 } 390 if (login_list_contains(chap_a, "5") == 0) { 391 login_send_error(request, 0x02, 0x01); 392 log_errx(1, "received CHAP Login PDU with unsupported CHAP_A " 393 "\"%s\"", chap_a); 394 } 395 keys_delete(request_keys); 396 397 return (request); 398} 399 400static void 401login_send_chap_c(struct pdu *request, const unsigned char id, 402 const void *challenge, const size_t challenge_len) 403{ 404 struct pdu *response; 405 struct keys *response_keys; 406 char *chap_c, chap_i[4]; 407 408 chap_c = login_bin2hex(challenge, challenge_len); 409 snprintf(chap_i, sizeof(chap_i), "%d", id); 410 411 response = login_new_response(request); 412 response_keys = keys_new(); 413 keys_add(response_keys, "CHAP_A", "5"); 414 keys_add(response_keys, "CHAP_I", chap_i); 415 keys_add(response_keys, "CHAP_C", chap_c); 416 free(chap_c); 417 keys_save(response_keys, response); 418 pdu_send(response); 419 pdu_delete(response); 420 keys_delete(response_keys); 421} 422 423static struct pdu * 424login_receive_chap_r(struct connection *conn, 425 struct auth_group *ag, const unsigned char id, const void *challenge, 426 const size_t challenge_len, const struct auth **cap) 427{ 428 struct pdu *request; 429 struct keys *request_keys; 430 const char *chap_n, *chap_r; 431 char *response_bin, expected_response_bin[MD5_DIGEST_LENGTH]; 432 size_t response_bin_len; 433 const struct auth *auth; 434 int error; 435 436 request = login_receive(conn, false); 437 request_keys = keys_new(); 438 keys_load(request_keys, request); 439 440 chap_n = keys_find(request_keys, "CHAP_N"); 441 if (chap_n == NULL) { 442 login_send_error(request, 0x02, 0x07); 443 log_errx(1, "received CHAP Login PDU without CHAP_N"); 444 } 445 chap_r = keys_find(request_keys, "CHAP_R"); 446 if (chap_r == NULL) { 447 login_send_error(request, 0x02, 0x07); 448 log_errx(1, "received CHAP Login PDU without CHAP_R"); 449 } 450 error = login_hex2bin(chap_r, &response_bin, &response_bin_len); 451 if (error != 0) { 452 login_send_error(request, 0x02, 0x07); 453 log_errx(1, "received CHAP Login PDU with malformed CHAP_R"); 454 } 455 456 /* 457 * Verify the response. 458 */ 459 assert(ag->ag_type == AG_TYPE_CHAP || 460 ag->ag_type == AG_TYPE_CHAP_MUTUAL); 461 auth = auth_find(ag, chap_n); 462 if (auth == NULL) { 463 login_send_error(request, 0x02, 0x01); 464 log_errx(1, "received CHAP Login with invalid user \"%s\"", 465 chap_n); 466 } 467 468 assert(auth->a_secret != NULL); 469 assert(strlen(auth->a_secret) > 0); 470 login_compute_md5(id, auth->a_secret, challenge, 471 challenge_len, expected_response_bin, 472 sizeof(expected_response_bin)); 473 474 if (memcmp(response_bin, expected_response_bin, 475 sizeof(expected_response_bin)) != 0) { 476 login_send_error(request, 0x02, 0x01); 477 log_errx(1, "CHAP authentication failed for user \"%s\"", 478 auth->a_user); 479 } 480 481 keys_delete(request_keys); 482 free(response_bin); 483 484 *cap = auth; 485 return (request); 486} 487 488static void 489login_send_chap_success(struct pdu *request, 490 const struct auth *auth) 491{ 492 struct pdu *response; 493 struct keys *request_keys, *response_keys; 494 struct iscsi_bhs_login_response *bhslr2; 495 const char *chap_i, *chap_c; 496 char *chap_r, *challenge, response_bin[MD5_DIGEST_LENGTH]; 497 size_t challenge_len; 498 unsigned char id; 499 int error; 500 501 response = login_new_response(request); 502 bhslr2 = (struct iscsi_bhs_login_response *)response->pdu_bhs; 503 bhslr2->bhslr_flags |= BHSLR_FLAGS_TRANSIT; 504 login_set_nsg(response, BHSLR_STAGE_OPERATIONAL_NEGOTIATION); 505 506 /* 507 * Actually, one more thing: mutual authentication. 508 */ 509 request_keys = keys_new(); 510 keys_load(request_keys, request); 511 chap_i = keys_find(request_keys, "CHAP_I"); 512 chap_c = keys_find(request_keys, "CHAP_C"); 513 if (chap_i != NULL || chap_c != NULL) { 514 if (chap_i == NULL) { 515 login_send_error(request, 0x02, 0x07); 516 log_errx(1, "initiator requested target " 517 "authentication, but didn't send CHAP_I"); 518 } 519 if (chap_c == NULL) { 520 login_send_error(request, 0x02, 0x07); 521 log_errx(1, "initiator requested target " 522 "authentication, but didn't send CHAP_C"); 523 } 524 if (auth->a_auth_group->ag_type != AG_TYPE_CHAP_MUTUAL) { 525 login_send_error(request, 0x02, 0x01); 526 log_errx(1, "initiator requests target authentication " 527 "for user \"%s\", but mutual user/secret " 528 "is not set", auth->a_user); 529 } 530 531 id = strtoul(chap_i, NULL, 10); 532 error = login_hex2bin(chap_c, &challenge, &challenge_len); 533 if (error != 0) { 534 login_send_error(request, 0x02, 0x07); 535 log_errx(1, "received CHAP Login PDU with malformed " 536 "CHAP_C"); 537 } 538 539 log_debugx("performing mutual authentication as user \"%s\"", 540 auth->a_mutual_user); 541 login_compute_md5(id, auth->a_mutual_secret, challenge, 542 challenge_len, response_bin, sizeof(response_bin)); 543 544 chap_r = login_bin2hex(response_bin, 545 sizeof(response_bin)); 546 response_keys = keys_new(); 547 keys_add(response_keys, "CHAP_N", auth->a_mutual_user); 548 keys_add(response_keys, "CHAP_R", chap_r); 549 free(chap_r); 550 keys_save(response_keys, response); 551 keys_delete(response_keys); 552 } else { 553 log_debugx("initiator did not request target authentication"); 554 } 555 556 keys_delete(request_keys); 557 pdu_send(response); 558 pdu_delete(response); 559} 560 561static void 562login_chap(struct connection *conn, struct auth_group *ag) 563{ 564 const struct auth *auth; 565 struct pdu *request; 566 char challenge_bin[LOGIN_CHALLENGE_LEN]; 567 unsigned char id; 568 int rv; 569 570 /* 571 * Receive CHAP_A PDU. 572 */ 573 log_debugx("beginning CHAP authentication; waiting for CHAP_A"); 574 request = login_receive_chap_a(conn); 575 576 /* 577 * Generate the challenge. 578 */ 579 rv = RAND_bytes(challenge_bin, sizeof(challenge_bin)); 580 if (rv != 1) { 581 login_send_error(request, 0x03, 0x02); 582 log_errx(1, "RAND_bytes failed: %s", 583 ERR_error_string(ERR_get_error(), NULL)); 584 } 585 rv = RAND_bytes(&id, sizeof(id)); 586 if (rv != 1) { 587 login_send_error(request, 0x03, 0x02); 588 log_errx(1, "RAND_bytes failed: %s", 589 ERR_error_string(ERR_get_error(), NULL)); 590 } 591 592 /* 593 * Send the challenge. 594 */ 595 log_debugx("sending CHAP_C, binary challenge size is %zd bytes", 596 sizeof(challenge_bin)); 597 login_send_chap_c(request, id, challenge_bin, 598 sizeof(challenge_bin)); 599 pdu_delete(request); 600 601 /* 602 * Receive CHAP_N/CHAP_R PDU and authenticate. 603 */ 604 log_debugx("waiting for CHAP_N/CHAP_R"); 605 request = login_receive_chap_r(conn, ag, id, challenge_bin, 606 sizeof(challenge_bin), &auth); 607 608 /* 609 * Yay, authentication succeeded! 610 */ 611 log_debugx("authentication succeeded for user \"%s\"; " 612 "transitioning to Negotiation Phase", auth->a_user); 613 login_send_chap_success(request, auth); 614 pdu_delete(request); 615} 616 617static void 618login_negotiate_key(struct pdu *request, const char *name, 619 const char *value, bool skipped_security, struct keys *response_keys) 620{ 621 int which, tmp; 622 struct connection *conn; 623 624 conn = request->pdu_connection; 625 626 if (strcmp(name, "InitiatorName") == 0) { 627 if (!skipped_security) 628 log_errx(1, "initiator resent InitiatorName"); 629 } else if (strcmp(name, "SessionType") == 0) { 630 if (!skipped_security) 631 log_errx(1, "initiator resent SessionType"); 632 } else if (strcmp(name, "TargetName") == 0) { 633 if (!skipped_security) 634 log_errx(1, "initiator resent TargetName"); 635 } else if (strcmp(name, "InitiatorAlias") == 0) { 636 if (conn->conn_initiator_alias != NULL) 637 free(conn->conn_initiator_alias); 638 conn->conn_initiator_alias = checked_strdup(value); 639 } else if (strcmp(value, "Irrelevant") == 0) { 640 /* Ignore. */ 641 } else if (strcmp(name, "HeaderDigest") == 0) { 642 /* 643 * We don't handle digests for discovery sessions. 644 */ 645 if (conn->conn_session_type == CONN_SESSION_TYPE_DISCOVERY) { 646 log_debugx("discovery session; digests disabled"); 647 keys_add(response_keys, name, "None"); 648 return; 649 } 650 651 which = login_list_prefers(value, "CRC32C", "None"); 652 switch (which) { 653 case 1: 654 log_debugx("initiator prefers CRC32C " 655 "for header digest; we'll use it"); 656 conn->conn_header_digest = CONN_DIGEST_CRC32C; 657 keys_add(response_keys, name, "CRC32C"); 658 break; 659 case 2: 660 log_debugx("initiator prefers not to do " 661 "header digest; we'll comply"); 662 keys_add(response_keys, name, "None"); 663 break; 664 default: 665 log_warnx("initiator sent unrecognized " 666 "HeaderDigest value \"%s\"; will use None", value); 667 keys_add(response_keys, name, "None"); 668 break; 669 } 670 } else if (strcmp(name, "DataDigest") == 0) { 671 if (conn->conn_session_type == CONN_SESSION_TYPE_DISCOVERY) { 672 log_debugx("discovery session; digests disabled"); 673 keys_add(response_keys, name, "None"); 674 return; 675 } 676 677 which = login_list_prefers(value, "CRC32C", "None"); 678 switch (which) { 679 case 1: 680 log_debugx("initiator prefers CRC32C " 681 "for data digest; we'll use it"); 682 conn->conn_data_digest = CONN_DIGEST_CRC32C; 683 keys_add(response_keys, name, "CRC32C"); 684 break; 685 case 2: 686 log_debugx("initiator prefers not to do " 687 "data digest; we'll comply"); 688 keys_add(response_keys, name, "None"); 689 break; 690 default: 691 log_warnx("initiator sent unrecognized " 692 "DataDigest value \"%s\"; will use None", value); 693 keys_add(response_keys, name, "None"); 694 break; 695 } 696 } else if (strcmp(name, "MaxConnections") == 0) { 697 keys_add(response_keys, name, "1"); 698 } else if (strcmp(name, "InitialR2T") == 0) { 699 keys_add(response_keys, name, "Yes"); 700 } else if (strcmp(name, "ImmediateData") == 0) { 701 if (conn->conn_session_type == CONN_SESSION_TYPE_DISCOVERY) { 702 log_debugx("discovery session; ImmediateData irrelevant"); 703 keys_add(response_keys, name, "Irrelevant"); 704 } else { 705 if (strcmp(value, "Yes") == 0) { 706 conn->conn_immediate_data = true; 707 keys_add(response_keys, name, "Yes"); 708 } else { 709 conn->conn_immediate_data = false; 710 keys_add(response_keys, name, "No"); 711 } 712 } 713 } else if (strcmp(name, "MaxRecvDataSegmentLength") == 0) { 714 tmp = strtoul(value, NULL, 10); 715 if (tmp <= 0) { 716 login_send_error(request, 0x02, 0x00); 717 log_errx(1, "received invalid " 718 "MaxRecvDataSegmentLength"); 719 } 720 if (tmp > MAX_DATA_SEGMENT_LENGTH) { 721 log_debugx("capping MaxDataSegmentLength from %d to %d", 722 tmp, MAX_DATA_SEGMENT_LENGTH); 723 tmp = MAX_DATA_SEGMENT_LENGTH; 724 } 725 conn->conn_max_data_segment_length = tmp; 726 keys_add_int(response_keys, name, tmp); 727 } else if (strcmp(name, "MaxBurstLength") == 0) { 728 tmp = strtoul(value, NULL, 10); 729 if (tmp <= 0) { 730 login_send_error(request, 0x02, 0x00); 731 log_errx(1, "received invalid MaxBurstLength"); 732 } 733 if (tmp > MAX_BURST_LENGTH) { 734 log_debugx("capping MaxBurstLength from %d to %d", 735 tmp, MAX_BURST_LENGTH); 736 tmp = MAX_BURST_LENGTH; 737 } 738 conn->conn_max_burst_length = tmp; 739 keys_add(response_keys, name, value); 740 } else if (strcmp(name, "FirstBurstLength") == 0) { 741 tmp = strtoul(value, NULL, 10); 742 if (tmp <= 0) { 743 login_send_error(request, 0x02, 0x00); 744 log_errx(1, "received invalid " 745 "FirstBurstLength"); 746 } 747 if (tmp > MAX_DATA_SEGMENT_LENGTH) { 748 log_debugx("capping FirstBurstLength from %d to %d", 749 tmp, MAX_DATA_SEGMENT_LENGTH); 750 tmp = MAX_DATA_SEGMENT_LENGTH; 751 } 752 /* 753 * We don't pass the value to the kernel; it only enforces 754 * hardcoded limit anyway. 755 */ 756 keys_add_int(response_keys, name, tmp); 757 } else if (strcmp(name, "DefaultTime2Wait") == 0) { 758 keys_add(response_keys, name, value); 759 } else if (strcmp(name, "DefaultTime2Retain") == 0) { 760 keys_add(response_keys, name, "0"); 761 } else if (strcmp(name, "MaxOutstandingR2T") == 0) { 762 keys_add(response_keys, name, "1"); 763 } else if (strcmp(name, "DataPDUInOrder") == 0) { 764 keys_add(response_keys, name, "Yes"); 765 } else if (strcmp(name, "DataSequenceInOrder") == 0) { 766 keys_add(response_keys, name, "Yes"); 767 } else if (strcmp(name, "ErrorRecoveryLevel") == 0) { 768 keys_add(response_keys, name, "0"); 769 } else if (strcmp(name, "OFMarker") == 0) { 770 keys_add(response_keys, name, "No"); 771 } else if (strcmp(name, "IFMarker") == 0) { 772 keys_add(response_keys, name, "No"); 773 } else { 774 log_debugx("unknown key \"%s\"; responding " 775 "with NotUnderstood", name); 776 keys_add(response_keys, name, "NotUnderstood"); 777 } 778} 779 780static void 781login_negotiate(struct connection *conn, struct pdu *request) 782{ 783 struct pdu *response; 784 struct iscsi_bhs_login_response *bhslr2; 785 struct keys *request_keys, *response_keys; 786 int i; 787 bool skipped_security; 788 789 if (request == NULL) { 790 log_debugx("beginning operational parameter negotiation; " 791 "waiting for Login PDU"); 792 request = login_receive(conn, false); 793 skipped_security = false; 794 } else 795 skipped_security = true; 796 797 request_keys = keys_new(); 798 keys_load(request_keys, request); 799 800 response = login_new_response(request); 801 bhslr2 = (struct iscsi_bhs_login_response *)response->pdu_bhs; 802 bhslr2->bhslr_flags |= BHSLR_FLAGS_TRANSIT; 803 bhslr2->bhslr_tsih = htons(0xbadd); 804 login_set_csg(response, BHSLR_STAGE_OPERATIONAL_NEGOTIATION); 805 login_set_nsg(response, BHSLR_STAGE_FULL_FEATURE_PHASE); 806 response_keys = keys_new(); 807 for (i = 0; i < KEYS_MAX; i++) { 808 if (request_keys->keys_names[i] == NULL) 809 break; 810 811 login_negotiate_key(request, request_keys->keys_names[i], 812 request_keys->keys_values[i], skipped_security, 813 response_keys); 814 } 815 816 log_debugx("operational parameter negotiation done; " 817 "transitioning to Full Feature Phase"); 818 819 keys_save(response_keys, response); 820 pdu_send(response); 821 pdu_delete(response); 822 keys_delete(response_keys); 823 pdu_delete(request); 824 keys_delete(request_keys); 825} 826 827void 828login(struct connection *conn) 829{ 830 struct pdu *request, *response; 831 struct iscsi_bhs_login_request *bhslr; 832 struct iscsi_bhs_login_response *bhslr2; 833 struct keys *request_keys, *response_keys; 834 struct auth_group *ag; 835 const char *initiator_name, *initiator_alias, *session_type, 836 *target_name, *auth_method; 837 char *portal_group_tag; 838 int rv; 839 840 /* 841 * Handle the initial Login Request - figure out required authentication 842 * method and either transition to the next phase, if no authentication 843 * is required, or call appropriate authentication code. 844 */ 845 log_debugx("beginning Login Phase; waiting for Login PDU"); 846 request = login_receive(conn, true); 847 bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs; 848 if (bhslr->bhslr_tsih != 0) { 849 login_send_error(request, 0x02, 0x0a); 850 log_errx(1, "received Login PDU with non-zero TSIH"); 851 } 852 853 memcpy(conn->conn_initiator_isid, bhslr->bhslr_isid, 854 sizeof(conn->conn_initiator_isid)); 855 856 /* 857 * XXX: Implement the C flag some day. 858 */ 859 request_keys = keys_new(); 860 keys_load(request_keys, request); 861 862 assert(conn->conn_initiator_name == NULL); 863 initiator_name = keys_find(request_keys, "InitiatorName"); 864 if (initiator_name == NULL) { 865 login_send_error(request, 0x02, 0x07); 866 log_errx(1, "received Login PDU without InitiatorName"); 867 } 868 if (valid_iscsi_name(initiator_name) == false) { 869 login_send_error(request, 0x02, 0x00); 870 log_errx(1, "received Login PDU with invalid InitiatorName"); 871 } 872 conn->conn_initiator_name = checked_strdup(initiator_name); 873 log_set_peer_name(conn->conn_initiator_name); 874 /* 875 * XXX: This doesn't work (does nothing) because of Capsicum. 876 */ 877 setproctitle("%s (%s)", conn->conn_initiator_addr, conn->conn_initiator_name); 878 879 initiator_alias = keys_find(request_keys, "InitiatorAlias"); 880 if (initiator_alias != NULL) 881 conn->conn_initiator_alias = checked_strdup(initiator_alias); 882 883 assert(conn->conn_session_type == CONN_SESSION_TYPE_NONE); 884 session_type = keys_find(request_keys, "SessionType"); 885 if (session_type != NULL) { 886 if (strcmp(session_type, "Normal") == 0) { 887 conn->conn_session_type = CONN_SESSION_TYPE_NORMAL; 888 } else if (strcmp(session_type, "Discovery") == 0) { 889 conn->conn_session_type = CONN_SESSION_TYPE_DISCOVERY; 890 } else { 891 login_send_error(request, 0x02, 0x00); 892 log_errx(1, "received Login PDU with invalid " 893 "SessionType \"%s\"", session_type); 894 } 895 } else 896 conn->conn_session_type = CONN_SESSION_TYPE_NORMAL; 897 898 assert(conn->conn_target == NULL); 899 if (conn->conn_session_type == CONN_SESSION_TYPE_NORMAL) { 900 target_name = keys_find(request_keys, "TargetName"); 901 if (target_name == NULL) { 902 login_send_error(request, 0x02, 0x07); 903 log_errx(1, "received Login PDU without TargetName"); 904 } 905 906 conn->conn_target = 907 target_find(conn->conn_portal->p_portal_group->pg_conf, 908 target_name); 909 if (conn->conn_target == NULL) { 910 login_send_error(request, 0x02, 0x03); 911 log_errx(1, "requested target \"%s\" not found", 912 target_name); 913 } 914 } 915 916 /* 917 * At this point we know what kind of authentication we need. 918 */ 919 if (conn->conn_session_type == CONN_SESSION_TYPE_NORMAL) { 920 ag = conn->conn_target->t_auth_group; 921 if (ag->ag_name != NULL) { 922 log_debugx("initiator requests to connect " 923 "to target \"%s\"; auth-group \"%s\"", 924 conn->conn_target->t_name, 925 conn->conn_target->t_auth_group->ag_name); 926 } else { 927 log_debugx("initiator requests to connect " 928 "to target \"%s\"", conn->conn_target->t_name); 929 } 930 } else { 931 assert(conn->conn_session_type == CONN_SESSION_TYPE_DISCOVERY); 932 ag = conn->conn_portal->p_portal_group->pg_discovery_auth_group; 933 if (ag->ag_name != NULL) { 934 log_debugx("initiator requests " 935 "discovery session; auth-group \"%s\"", ag->ag_name); 936 } else { 937 log_debugx("initiator requests discovery session"); 938 } 939 } 940 941 /* 942 * Enforce initiator-name and initiator-portal. 943 */ 944 if (auth_name_defined(ag)) { 945 if (auth_name_find(ag, initiator_name) == NULL) { 946 login_send_error(request, 0x02, 0x02); 947 log_errx(1, "initiator does not match allowed " 948 "initiator names"); 949 } 950 log_debugx("initiator matches allowed initiator names"); 951 } else { 952 log_debugx("auth-group does not define initiator name " 953 "restrictions"); 954 } 955 956 if (auth_portal_defined(ag)) { 957 if (auth_portal_find(ag, &conn->conn_initiator_sa) == NULL) { 958 login_send_error(request, 0x02, 0x02); 959 log_errx(1, "initiator does not match allowed " 960 "initiator portals"); 961 } 962 log_debugx("initiator matches allowed initiator portals"); 963 } else { 964 log_debugx("auth-group does not define initiator portal " 965 "restrictions"); 966 } 967 968 /* 969 * Let's see if the initiator intends to do any kind of authentication 970 * at all. 971 */ 972 if (login_csg(request) == BHSLR_STAGE_OPERATIONAL_NEGOTIATION) { 973 if (ag->ag_type != AG_TYPE_NO_AUTHENTICATION) { 974 login_send_error(request, 0x02, 0x01); 975 log_errx(1, "initiator skipped the authentication, " 976 "but authentication is required"); 977 } 978 979 keys_delete(request_keys); 980 981 log_debugx("initiator skipped the authentication, " 982 "and we don't need it; proceeding with negotiation"); 983 login_negotiate(conn, request); 984 return; 985 } 986 987 if (ag->ag_type == AG_TYPE_NO_AUTHENTICATION) { 988 /* 989 * Initiator might want to to authenticate, 990 * but we don't need it. 991 */ 992 log_debugx("authentication not required; " 993 "transitioning to operational parameter negotiation"); 994 995 if ((bhslr->bhslr_flags & BHSLR_FLAGS_TRANSIT) == 0) 996 log_warnx("initiator did not set the \"T\" flag; " 997 "transitioning anyway"); 998 999 response = login_new_response(request); 1000 bhslr2 = (struct iscsi_bhs_login_response *)response->pdu_bhs; 1001 bhslr2->bhslr_flags |= BHSLR_FLAGS_TRANSIT; 1002 login_set_nsg(response, 1003 BHSLR_STAGE_OPERATIONAL_NEGOTIATION); 1004 response_keys = keys_new(); 1005 /* 1006 * Required by Linux initiator. 1007 */ 1008 auth_method = keys_find(request_keys, "AuthMethod"); 1009 if (auth_method != NULL && 1010 login_list_contains(auth_method, "None")) 1011 keys_add(response_keys, "AuthMethod", "None"); 1012 1013 if (conn->conn_session_type == CONN_SESSION_TYPE_NORMAL) { 1014 if (conn->conn_target->t_alias != NULL) 1015 keys_add(response_keys, 1016 "TargetAlias", conn->conn_target->t_alias); 1017 rv = asprintf(&portal_group_tag, "%d", 1018 conn->conn_portal->p_portal_group->pg_tag); 1019 if (rv <= 0) 1020 log_err(1, "asprintf"); 1021 keys_add(response_keys, 1022 "TargetPortalGroupTag", portal_group_tag); 1023 free(portal_group_tag); 1024 } 1025 keys_save(response_keys, response); 1026 pdu_send(response); 1027 pdu_delete(response); 1028 keys_delete(response_keys); 1029 pdu_delete(request); 1030 keys_delete(request_keys); 1031 1032 login_negotiate(conn, NULL); 1033 return; 1034 } 1035 1036 if (ag->ag_type == AG_TYPE_DENY) { 1037 login_send_error(request, 0x02, 0x01); 1038 log_errx(1, "auth-type is \"deny\""); 1039 } 1040 1041 if (ag->ag_type == AG_TYPE_UNKNOWN) { 1042 /* 1043 * This can happen with empty auth-group. 1044 */ 1045 login_send_error(request, 0x02, 0x01); 1046 log_errx(1, "auth-type not set, denying access"); 1047 } 1048 1049 log_debugx("CHAP authentication required"); 1050 1051 auth_method = keys_find(request_keys, "AuthMethod"); 1052 if (auth_method == NULL) { 1053 login_send_error(request, 0x02, 0x07); 1054 log_errx(1, "received Login PDU without AuthMethod"); 1055 } 1056 /* 1057 * XXX: This should be Reject, not just a login failure (5.3.2). 1058 */ 1059 if (login_list_contains(auth_method, "CHAP") == 0) { 1060 login_send_error(request, 0x02, 0x01); 1061 log_errx(1, "initiator requests unsupported AuthMethod \"%s\" " 1062 "instead of \"CHAP\"", auth_method); 1063 } 1064 1065 response = login_new_response(request); 1066 1067 response_keys = keys_new(); 1068 keys_add(response_keys, "AuthMethod", "CHAP"); 1069 if (conn->conn_session_type == CONN_SESSION_TYPE_NORMAL) { 1070 rv = asprintf(&portal_group_tag, "%d", 1071 conn->conn_portal->p_portal_group->pg_tag); 1072 if (rv <= 0) 1073 log_err(1, "asprintf"); 1074 keys_add(response_keys, 1075 "TargetPortalGroupTag", portal_group_tag); 1076 free(portal_group_tag); 1077 if (conn->conn_target->t_alias != NULL) 1078 keys_add(response_keys, 1079 "TargetAlias", conn->conn_target->t_alias); 1080 } 1081 keys_save(response_keys, response); 1082 1083 pdu_send(response); 1084 pdu_delete(response); 1085 keys_delete(response_keys); 1086 pdu_delete(request); 1087 keys_delete(request_keys); 1088 1089 login_chap(conn, ag); 1090 1091 login_negotiate(conn, NULL); 1092} 1093