usr.sbin/ctld/login.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
   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 __FBSDID("$FreeBSD$");
  34
  35 #include <assert.h>
  36 #include <stdbool.h>
  37 #include <stdlib.h>
  38 #include <string.h>
  39 #include <unistd.h>
  40 #include <netinet/in.h>
  41
  42 #include "ctld.h"
  43 #include "iscsi_proto.h"
  44
  45 static void login_send_error(struct pdu *request,
  46     char class, char detail);
  47
  48 static void
  49 login_set_nsg(struct pdu *response, int nsg)
  50 {
  51         struct iscsi_bhs_login_response *bhslr;
  52
  53         assert(nsg == BHSLR_STAGE_SECURITY_NEGOTIATION ||
  54             nsg == BHSLR_STAGE_OPERATIONAL_NEGOTIATION ||
  55             nsg == BHSLR_STAGE_FULL_FEATURE_PHASE);
  56
  57         bhslr = (struct iscsi_bhs_login_response *)response->pdu_bhs;
  58
  59         bhslr->bhslr_flags &= 0xFC;
  60         bhslr->bhslr_flags |= nsg;
  61         bhslr->bhslr_flags |= BHSLR_FLAGS_TRANSIT;
  62 }
  63
  64 static int
  65 login_csg(const struct pdu *request)
  66 {
  67         struct iscsi_bhs_login_request *bhslr;
  68
  69         bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs;
  70
  71         return ((bhslr->bhslr_flags & 0x0C) >> 2);
  72 }
  73
  74 static void
  75 login_set_csg(struct pdu *response, int csg)
  76 {
  77         struct iscsi_bhs_login_response *bhslr;
  78
  79         assert(csg == BHSLR_STAGE_SECURITY_NEGOTIATION ||
  80             csg == BHSLR_STAGE_OPERATIONAL_NEGOTIATION ||
  81             csg == BHSLR_STAGE_FULL_FEATURE_PHASE);
  82
  83         bhslr = (struct iscsi_bhs_login_response *)response->pdu_bhs;
  84
  85         bhslr->bhslr_flags &= 0xF3;
  86         bhslr->bhslr_flags |= csg << 2;
  87 }
  88
  89 static struct pdu *
  90 login_receive(struct connection *conn, bool initial)
  91 {
  92         struct pdu *request;
  93         struct iscsi_bhs_login_request *bhslr;
  94
  95         request = pdu_new(conn);
  96         pdu_receive(request);
  97         if ((request->pdu_bhs->bhs_opcode & ~ISCSI_BHS_OPCODE_IMMEDIATE) !=
  98             ISCSI_BHS_OPCODE_LOGIN_REQUEST) {
  99                 /*
 100                  * The first PDU in session is special - if we receive any PDU
 101                  * different than login request, we have to drop the connection
 102                  * without sending response ("A target receiving any PDU
 103                  * except a Login request before the Login Phase is started MUST
 104                  * immediately terminate the connection on which the PDU
 105                  * was received.")
 106                  */
 107                 if (initial == false)
 108                         login_send_error(request, 0x02, 0x0b);
 109                 log_errx(1, "protocol error: received invalid opcode 0x%x",
 110                     request->pdu_bhs->bhs_opcode);
 111         }
 112         bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs;
 113         /*
 114          * XXX: Implement the C flag some day.
 115          */
 116         if ((bhslr->bhslr_flags & BHSLR_FLAGS_CONTINUE) != 0) {
 117                 login_send_error(request, 0x03, 0x00);
 118                 log_errx(1, "received Login PDU with unsupported \"C\" flag");
 119         }
 120         if (bhslr->bhslr_version_max != 0x00) {
 121                 login_send_error(request, 0x02, 0x05);
 122                 log_errx(1, "received Login PDU with unsupported "
 123                     "Version-max 0x%x", bhslr->bhslr_version_max);
 124         }
 125         if (bhslr->bhslr_version_min != 0x00) {
 126                 login_send_error(request, 0x02, 0x05);
 127                 log_errx(1, "received Login PDU with unsupported "
 128                     "Version-min 0x%x", bhslr->bhslr_version_min);
 129         }
 130         if (initial == false &&
 131             ISCSI_SNLT(ntohl(bhslr->bhslr_cmdsn), conn->conn_cmdsn)) {
 132                 login_send_error(request, 0x02, 0x00);
 133                 log_errx(1, "received Login PDU with decreasing CmdSN: "
 134                     "was %u, is %u", 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, 0x00);
 140                 log_errx(1, "received Login PDU with wrong ExpStatSN: "
 141                     "is %u, should be %u", ntohl(bhslr->bhslr_expstatsn),
 142                     conn->conn_statsn);
 143         }
 144         conn->conn_cmdsn = ntohl(bhslr->bhslr_cmdsn);
 145
 146         return (request);
 147 }
 148
 149 static struct pdu *
 150 login_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
 174 static void
 175 login_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
 191 static int
 192 login_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
 208 static int
 209 login_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
 230 static struct pdu *
 231 login_receive_chap_a(struct connection *conn)
 232 {
 233         struct pdu *request;
 234         struct keys *request_keys;
 235         const char *chap_a;
 236
 237         request = login_receive(conn, false);
 238         request_keys = keys_new();
 239         keys_load(request_keys, request);
 240
 241         chap_a = keys_find(request_keys, "CHAP_A");
 242         if (chap_a == NULL) {
 243                 login_send_error(request, 0x02, 0x07);
 244                 log_errx(1, "received CHAP Login PDU without CHAP_A");
 245         }
 246         if (login_list_contains(chap_a, "5") == 0) {
 247                 login_send_error(request, 0x02, 0x01);
 248                 log_errx(1, "received CHAP Login PDU with unsupported CHAP_A "
 249                     "\"%s\"", chap_a);
 250         }
 251         keys_delete(request_keys);
 252
 253         return (request);
 254 }
 255
 256 static void
 257 login_send_chap_c(struct pdu *request, struct chap *chap)
 258 {
 259         struct pdu *response;
 260         struct keys *response_keys;
 261         char *chap_c, *chap_i;
 262
 263         chap_c = chap_get_challenge(chap);
 264         chap_i = chap_get_id(chap);
 265
 266         response = login_new_response(request);
 267         response_keys = keys_new();
 268         keys_add(response_keys, "CHAP_A", "5");
 269         keys_add(response_keys, "CHAP_I", chap_i);
 270         keys_add(response_keys, "CHAP_C", chap_c);
 271         free(chap_i);
 272         free(chap_c);
 273         keys_save(response_keys, response);
 274         pdu_send(response);
 275         pdu_delete(response);
 276         keys_delete(response_keys);
 277 }
 278
 279 static struct pdu *
 280 login_receive_chap_r(struct connection *conn, struct auth_group *ag,
 281     struct chap *chap, const struct auth **authp)
 282 {
 283         struct pdu *request;
 284         struct keys *request_keys;
 285         const char *chap_n, *chap_r;
 286         const struct auth *auth;
 287         int error;
 288
 289         request = login_receive(conn, false);
 290         request_keys = keys_new();
 291         keys_load(request_keys, request);
 292
 293         chap_n = keys_find(request_keys, "CHAP_N");
 294         if (chap_n == NULL) {
 295                 login_send_error(request, 0x02, 0x07);
 296                 log_errx(1, "received CHAP Login PDU without CHAP_N");
 297         }
 298         chap_r = keys_find(request_keys, "CHAP_R");
 299         if (chap_r == NULL) {
 300                 login_send_error(request, 0x02, 0x07);
 301                 log_errx(1, "received CHAP Login PDU without CHAP_R");
 302         }
 303         error = chap_receive(chap, chap_r);
 304         if (error != 0) {
 305                 login_send_error(request, 0x02, 0x07);
 306                 log_errx(1, "received CHAP Login PDU with malformed CHAP_R");
 307         }
 308
 309         /*
 310          * Verify the response.
 311          */
 312         assert(ag->ag_type == AG_TYPE_CHAP ||
 313             ag->ag_type == AG_TYPE_CHAP_MUTUAL);
 314         auth = auth_find(ag, chap_n);
 315         if (auth == NULL) {
 316                 login_send_error(request, 0x02, 0x01);
 317                 log_errx(1, "received CHAP Login with invalid user \"%s\"",
 318                     chap_n);
 319         }
 320
 321         assert(auth->a_secret != NULL);
 322         assert(strlen(auth->a_secret) > 0);
 323
 324         error = chap_authenticate(chap, auth->a_secret);
 325         if (error != 0) {
 326                 login_send_error(request, 0x02, 0x01);
 327                 log_errx(1, "CHAP authentication failed for user \"%s\"",
 328                     auth->a_user);
 329         }
 330
 331         keys_delete(request_keys);
 332
 333         *authp = auth;
 334         return (request);
 335 }
 336
 337 static void
 338 login_send_chap_success(struct pdu *request,
 339     const struct auth *auth)
 340 {
 341         struct pdu *response;
 342         struct keys *request_keys, *response_keys;
 343         struct rchap *rchap;
 344         const char *chap_i, *chap_c;
 345         char *chap_r;
 346         int error;
 347
 348         response = login_new_response(request);
 349         login_set_nsg(response, BHSLR_STAGE_OPERATIONAL_NEGOTIATION);
 350
 351         /*
 352          * Actually, one more thing: mutual authentication.
 353          */
 354         request_keys = keys_new();
 355         keys_load(request_keys, request);
 356         chap_i = keys_find(request_keys, "CHAP_I");
 357         chap_c = keys_find(request_keys, "CHAP_C");
 358         if (chap_i != NULL || chap_c != NULL) {
 359                 if (chap_i == NULL) {
 360                         login_send_error(request, 0x02, 0x07);
 361                         log_errx(1, "initiator requested target "
 362                             "authentication, but didn't send CHAP_I");
 363                 }
 364                 if (chap_c == NULL) {
 365                         login_send_error(request, 0x02, 0x07);
 366                         log_errx(1, "initiator requested target "
 367                             "authentication, but didn't send CHAP_C");
 368                 }
 369                 if (auth->a_auth_group->ag_type != AG_TYPE_CHAP_MUTUAL) {
 370                         login_send_error(request, 0x02, 0x01);
 371                         log_errx(1, "initiator requests target authentication "
 372                             "for user \"%s\", but mutual user/secret "
 373                             "is not set", auth->a_user);
 374                 }
 375
 376                 log_debugx("performing mutual authentication as user \"%s\"",
 377                     auth->a_mutual_user);
 378
 379                 rchap = rchap_new(auth->a_mutual_secret);
 380                 error = rchap_receive(rchap, chap_i, chap_c);
 381                 if (error != 0) {
 382                         login_send_error(request, 0x02, 0x07);
 383                         log_errx(1, "received CHAP Login PDU with malformed "
 384                             "CHAP_I or CHAP_C");
 385                 }
 386                 chap_r = rchap_get_response(rchap);
 387                 rchap_delete(rchap);
 388                 response_keys = keys_new();
 389                 keys_add(response_keys, "CHAP_N", auth->a_mutual_user);
 390                 keys_add(response_keys, "CHAP_R", chap_r);
 391                 free(chap_r);
 392                 keys_save(response_keys, response);
 393                 keys_delete(response_keys);
 394         } else {
 395                 log_debugx("initiator did not request target authentication");
 396         }
 397
 398         keys_delete(request_keys);
 399         pdu_send(response);
 400         pdu_delete(response);
 401 }
 402
 403 static void
 404 login_chap(struct connection *conn, struct auth_group *ag)
 405 {
 406         const struct auth *auth;
 407         struct chap *chap;
 408         struct pdu *request;
 409
 410         /*
 411          * Receive CHAP_A PDU.
 412          */
 413         log_debugx("beginning CHAP authentication; waiting for CHAP_A");
 414         request = login_receive_chap_a(conn);
 415
 416         /*
 417          * Generate the challenge.
 418          */
 419         chap = chap_new();
 420
 421         /*
 422          * Send the challenge.
 423          */
 424         log_debugx("sending CHAP_C, binary challenge size is %zd bytes",
 425             sizeof(chap->chap_challenge));
 426         login_send_chap_c(request, chap);
 427         pdu_delete(request);
 428
 429         /*
 430          * Receive CHAP_N/CHAP_R PDU and authenticate.
 431          */
 432         log_debugx("waiting for CHAP_N/CHAP_R");
 433         request = login_receive_chap_r(conn, ag, chap, &auth);
 434
 435         /*
 436          * Yay, authentication succeeded!
 437          */
 438         log_debugx("authentication succeeded for user \"%s\"; "
 439             "transitioning to operational parameter negotiation", auth->a_user);
 440         login_send_chap_success(request, auth);
 441         pdu_delete(request);
 442
 443         /*
 444          * Leave username and CHAP information for discovery().
 445          */
 446         conn->conn_user = auth->a_user;
 447         conn->conn_chap = chap;
 448 }
 449
 450 static void
 451 login_negotiate_key(struct pdu *request, const char *name,
 452     const char *value, bool skipped_security, struct keys *response_keys)
 453 {
 454         int which;
 455         size_t tmp;
 456         struct connection *conn;
 457
 458         conn = request->pdu_connection;
 459
 460         if (strcmp(name, "InitiatorName") == 0) {
 461                 if (!skipped_security)
 462                         log_errx(1, "initiator resent InitiatorName");
 463         } else if (strcmp(name, "SessionType") == 0) {
 464                 if (!skipped_security)
 465                         log_errx(1, "initiator resent SessionType");
 466         } else if (strcmp(name, "TargetName") == 0) {
 467                 if (!skipped_security)
 468                         log_errx(1, "initiator resent TargetName");
 469         } else if (strcmp(name, "InitiatorAlias") == 0) {
 470                 if (conn->conn_initiator_alias != NULL)
 471                         free(conn->conn_initiator_alias);
 472                 conn->conn_initiator_alias = checked_strdup(value);
 473         } else if (strcmp(value, "Irrelevant") == 0) {
 474                 /* Ignore. */
 475         } else if (strcmp(name, "HeaderDigest") == 0) {
 476                 /*
 477                  * We don't handle digests for discovery sessions.
 478                  */
 479                 if (conn->conn_session_type == CONN_SESSION_TYPE_DISCOVERY) {
 480                         log_debugx("discovery session; digests disabled");
 481                         keys_add(response_keys, name, "None");
 482                         return;
 483                 }
 484
 485                 which = login_list_prefers(value, "CRC32C", "None");
 486                 switch (which) {
 487                 case 1:
 488                         log_debugx("initiator prefers CRC32C "
 489                             "for header digest; we'll use it");
 490                         conn->conn_header_digest = CONN_DIGEST_CRC32C;
 491                         keys_add(response_keys, name, "CRC32C");
 492                         break;
 493                 case 2:
 494                         log_debugx("initiator prefers not to do "
 495                             "header digest; we'll comply");
 496                         keys_add(response_keys, name, "None");
 497                         break;
 498                 default:
 499                         log_warnx("initiator sent unrecognized "
 500                             "HeaderDigest value \"%s\"; will use None", value);
 501                         keys_add(response_keys, name, "None");
 502                         break;
 503                 }
 504         } else if (strcmp(name, "DataDigest") == 0) {
 505                 if (conn->conn_session_type == CONN_SESSION_TYPE_DISCOVERY) {
 506                         log_debugx("discovery session; digests disabled");
 507                         keys_add(response_keys, name, "None");
 508                         return;
 509                 }
 510
 511                 which = login_list_prefers(value, "CRC32C", "None");
 512                 switch (which) {
 513                 case 1:
 514                         log_debugx("initiator prefers CRC32C "
 515                             "for data digest; we'll use it");
 516                         conn->conn_data_digest = CONN_DIGEST_CRC32C;
 517                         keys_add(response_keys, name, "CRC32C");
 518                         break;
 519                 case 2:
 520                         log_debugx("initiator prefers not to do "
 521                             "data digest; we'll comply");
 522                         keys_add(response_keys, name, "None");
 523                         break;
 524                 default:
 525                         log_warnx("initiator sent unrecognized "
 526                             "DataDigest value \"%s\"; will use None", value);
 527                         keys_add(response_keys, name, "None");
 528                         break;
 529                 }
 530         } else if (strcmp(name, "MaxConnections") == 0) {
 531                 keys_add(response_keys, name, "1");
 532         } else if (strcmp(name, "InitialR2T") == 0) {
 533                 keys_add(response_keys, name, "Yes");
 534         } else if (strcmp(name, "ImmediateData") == 0) {
 535                 if (conn->conn_session_type == CONN_SESSION_TYPE_DISCOVERY) {
 536                         log_debugx("discovery session; ImmediateData irrelevant");
 537                         keys_add(response_keys, name, "Irrelevant");
 538                 } else {
 539                         if (strcmp(value, "Yes") == 0) {
 540                                 conn->conn_immediate_data = true;
 541                                 keys_add(response_keys, name, "Yes");
 542                         } else {
 543                                 conn->conn_immediate_data = false;
 544                                 keys_add(response_keys, name, "No");
 545                         }
 546                 }
 547         } else if (strcmp(name, "MaxRecvDataSegmentLength") == 0) {
 548                 tmp = strtoul(value, NULL, 10);
 549                 if (tmp <= 0) {
 550                         login_send_error(request, 0x02, 0x00);
 551                         log_errx(1, "received invalid "
 552                             "MaxRecvDataSegmentLength");
 553                 }
 554
 555                 /*
 556                  * MaxRecvDataSegmentLength is a direction-specific parameter.
 557                  * We'll limit our _send_ to what the initiator can handle but
 558                  * our MaxRecvDataSegmentLength is not influenced by the
 559                  * initiator in any way.
 560                  */
 561                 if ((int)tmp > conn->conn_max_send_data_segment_limit) {
 562                         log_debugx("capping MaxRecvDataSegmentLength "
 563                             "from %zd to %d", tmp,
 564                             conn->conn_max_send_data_segment_limit);
 565                         tmp = conn->conn_max_send_data_segment_limit;
 566                 }
 567                 conn->conn_max_send_data_segment_length = tmp;
 568                 conn->conn_max_recv_data_segment_length =
 569                     conn->conn_max_recv_data_segment_limit;
 570                 keys_add_int(response_keys, name,
 571                     conn->conn_max_recv_data_segment_length);
 572         } else if (strcmp(name, "MaxBurstLength") == 0) {
 573                 tmp = strtoul(value, NULL, 10);
 574                 if (tmp <= 0) {
 575                         login_send_error(request, 0x02, 0x00);
 576                         log_errx(1, "received invalid MaxBurstLength");
 577                 }
 578                 if ((int)tmp > conn->conn_max_burst_limit) {
 579                         log_debugx("capping MaxBurstLength from %zd to %d",
 580                             tmp, conn->conn_max_burst_limit);
 581                         tmp = conn->conn_max_burst_limit;
 582                 }
 583                 conn->conn_max_burst_length = tmp;
 584                 keys_add_int(response_keys, name, tmp);
 585         } else if (strcmp(name, "FirstBurstLength") == 0) {
 586                 tmp = strtoul(value, NULL, 10);
 587                 if (tmp <= 0) {
 588                         login_send_error(request, 0x02, 0x00);
 589                         log_errx(1, "received invalid FirstBurstLength");
 590                 }
 591                 if ((int)tmp > conn->conn_first_burst_limit) {
 592                         log_debugx("capping FirstBurstLength from %zd to %d",
 593                             tmp, conn->conn_first_burst_limit);
 594                         tmp = conn->conn_first_burst_limit;
 595                 }
 596                 conn->conn_first_burst_length = tmp;
 597                 keys_add_int(response_keys, name, tmp);
 598         } else if (strcmp(name, "DefaultTime2Wait") == 0) {
 599                 keys_add(response_keys, name, value);
 600         } else if (strcmp(name, "DefaultTime2Retain") == 0) {
 601                 keys_add(response_keys, name, "0");
 602         } else if (strcmp(name, "MaxOutstandingR2T") == 0) {
 603                 keys_add(response_keys, name, "1");
 604         } else if (strcmp(name, "DataPDUInOrder") == 0) {
 605                 keys_add(response_keys, name, "Yes");
 606         } else if (strcmp(name, "DataSequenceInOrder") == 0) {
 607                 keys_add(response_keys, name, "Yes");
 608         } else if (strcmp(name, "ErrorRecoveryLevel") == 0) {
 609                 keys_add(response_keys, name, "0");
 610         } else if (strcmp(name, "OFMarker") == 0) {
 611                 keys_add(response_keys, name, "No");
 612         } else if (strcmp(name, "IFMarker") == 0) {
 613                 keys_add(response_keys, name, "No");
 614         } else if (strcmp(name, "iSCSIProtocolLevel") == 0) {
 615                 tmp = strtoul(value, NULL, 10);
 616                 if (tmp > 2)
 617                         tmp = 2;
 618                 keys_add_int(response_keys, name, tmp);
 619         } else {
 620                 log_debugx("unknown key \"%s\"; responding "
 621                     "with NotUnderstood", name);
 622                 keys_add(response_keys, name, "NotUnderstood");
 623         }
 624 }
 625
 626 static void
 627 login_redirect(struct pdu *request, const char *target_address)
 628 {
 629         struct pdu *response;
 630         struct iscsi_bhs_login_response *bhslr2;
 631         struct keys *response_keys;
 632
 633         response = login_new_response(request);
 634         login_set_csg(response, login_csg(request));
 635         bhslr2 = (struct iscsi_bhs_login_response *)response->pdu_bhs;
 636         bhslr2->bhslr_status_class = 0x01;
 637         bhslr2->bhslr_status_detail = 0x01;
 638
 639         response_keys = keys_new();
 640         keys_add(response_keys, "TargetAddress", target_address);
 641
 642         keys_save(response_keys, response);
 643         pdu_send(response);
 644         pdu_delete(response);
 645         keys_delete(response_keys);
 646 }
 647
 648 static bool
 649 login_portal_redirect(struct connection *conn, struct pdu *request)
 650 {
 651         const struct portal_group *pg;
 652
 653         pg = conn->conn_portal->p_portal_group;
 654         if (pg->pg_redirection == NULL)
 655                 return (false);
 656
 657         log_debugx("portal-group \"%s\" configured to redirect to %s",
 658             pg->pg_name, pg->pg_redirection);
 659         login_redirect(request, pg->pg_redirection);
 660
 661         return (true);
 662 }
 663
 664 static bool
 665 login_target_redirect(struct connection *conn, struct pdu *request)
 666 {
 667         const char *target_address;
 668
 669         assert(conn->conn_portal->p_portal_group->pg_redirection == NULL);
 670
 671         if (conn->conn_target == NULL)
 672                 return (false);
 673
 674         target_address = conn->conn_target->t_redirection;
 675         if (target_address == NULL)
 676                 return (false);
 677
 678         log_debugx("target \"%s\" configured to redirect to %s",
 679           conn->conn_target->t_name, target_address);
 680         login_redirect(request, target_address);
 681
 682         return (true);
 683 }
 684
 685 static void
 686 login_negotiate(struct connection *conn, struct pdu *request)
 687 {
 688         struct pdu *response;
 689         struct iscsi_bhs_login_response *bhslr2;
 690         struct keys *request_keys, *response_keys;
 691         int i;
 692         bool redirected, skipped_security;
 693
 694         if (conn->conn_session_type == CONN_SESSION_TYPE_NORMAL) {
 695                 /*
 696                  * Query the kernel for various size limits.  In case of
 697                  * offload, it depends on hardware capabilities.
 698                  */
 699                 assert(conn->conn_target != NULL);
 700                 conn->conn_max_recv_data_segment_limit = (1 << 24) - 1;
 701                 conn->conn_max_send_data_segment_limit = (1 << 24) - 1;
 702                 conn->conn_max_burst_limit = (1 << 24) - 1;
 703                 conn->conn_first_burst_limit = (1 << 24) - 1;
 704                 kernel_limits(conn->conn_portal->p_portal_group->pg_offload,
 705                     &conn->conn_max_recv_data_segment_limit,
 706                     &conn->conn_max_send_data_segment_limit,
 707                     &conn->conn_max_burst_limit,
 708                     &conn->conn_first_burst_limit);
 709
 710                 /* We expect legal, usable values at this point. */
 711                 assert(conn->conn_max_recv_data_segment_limit >= 512);
 712                 assert(conn->conn_max_recv_data_segment_limit < (1 << 24));
 713                 assert(conn->conn_max_send_data_segment_limit >= 512);
 714                 assert(conn->conn_max_send_data_segment_limit < (1 << 24));
 715                 assert(conn->conn_max_burst_limit >= 512);
 716                 assert(conn->conn_max_burst_limit < (1 << 24));
 717                 assert(conn->conn_first_burst_limit >= 512);
 718                 assert(conn->conn_first_burst_limit < (1 << 24));
 719                 assert(conn->conn_first_burst_limit <=
 720                     conn->conn_max_burst_limit);
 721
 722                 /*
 723                  * Limit default send length in case it won't be negotiated.
 724                  * We can't do it for other limits, since they may affect both
 725                  * sender and receiver operation, and we must obey defaults.
 726                  */
 727                 if (conn->conn_max_send_data_segment_limit <
 728                     conn->conn_max_send_data_segment_length) {
 729                         conn->conn_max_send_data_segment_length =
 730                             conn->conn_max_send_data_segment_limit;
 731                 }
 732         } else {
 733                 conn->conn_max_recv_data_segment_limit =
 734                     MAX_DATA_SEGMENT_LENGTH;
 735                 conn->conn_max_send_data_segment_limit =
 736                     MAX_DATA_SEGMENT_LENGTH;
 737         }
 738
 739         if (request == NULL) {
 740                 log_debugx("beginning operational parameter negotiation; "
 741                     "waiting for Login PDU");
 742                 request = login_receive(conn, false);
 743                 skipped_security = false;
 744         } else
 745                 skipped_security = true;
 746
 747         /*
 748          * RFC 3720, 10.13.5.  Status-Class and Status-Detail, says
 749          * the redirection SHOULD be accepted by the initiator before
 750          * authentication, but MUST be accepted afterwards; that's
 751          * why we're doing it here and not earlier.
 752          */
 753         redirected = login_target_redirect(conn, request);
 754         if (redirected) {
 755                 log_debugx("initiator redirected; exiting");
 756                 exit(0);
 757         }
 758
 759         request_keys = keys_new();
 760         keys_load(request_keys, request);
 761
 762         response = login_new_response(request);
 763         bhslr2 = (struct iscsi_bhs_login_response *)response->pdu_bhs;
 764         bhslr2->bhslr_tsih = htons(0xbadd);
 765         login_set_csg(response, BHSLR_STAGE_OPERATIONAL_NEGOTIATION);
 766         login_set_nsg(response, BHSLR_STAGE_FULL_FEATURE_PHASE);
 767         response_keys = keys_new();
 768
 769         if (skipped_security &&
 770             conn->conn_session_type == CONN_SESSION_TYPE_NORMAL) {
 771                 if (conn->conn_target->t_alias != NULL)
 772                         keys_add(response_keys,
 773                             "TargetAlias", conn->conn_target->t_alias);
 774                 keys_add_int(response_keys, "TargetPortalGroupTag",
 775                     conn->conn_portal->p_portal_group->pg_tag);
 776         }
 777
 778         for (i = 0; i < KEYS_MAX; i++) {
 779                 if (request_keys->keys_names[i] == NULL)
 780                         break;
 781
 782                 login_negotiate_key(request, request_keys->keys_names[i],
 783                     request_keys->keys_values[i], skipped_security,
 784                     response_keys);
 785         }
 786
 787         /*
 788          * We'd started with usable values at our end.  But a bad initiator
 789          * could have presented a large FirstBurstLength and then a smaller
 790          * MaxBurstLength (in that order) and because we process the key/value
 791          * pairs in the order they are in the request we might have ended up
 792          * with illegal values here.
 793          */
 794         if (conn->conn_session_type == CONN_SESSION_TYPE_NORMAL &&
 795             conn->conn_first_burst_length > conn->conn_max_burst_length) {
 796                 log_errx(1, "initiator sent FirstBurstLength > MaxBurstLength");
 797         }
 798
 799         log_debugx("operational parameter negotiation done; "
 800             "transitioning to Full Feature Phase");
 801
 802         keys_save(response_keys, response);
 803         pdu_send(response);
 804         pdu_delete(response);
 805         keys_delete(response_keys);
 806         pdu_delete(request);
 807         keys_delete(request_keys);
 808 }
 809
 810 static void
 811 login_wait_transition(struct connection *conn)
 812 {
 813         struct pdu *request, *response;
 814         struct iscsi_bhs_login_request *bhslr;
 815
 816         log_debugx("waiting for state transition request");
 817         request = login_receive(conn, false);
 818         bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs;
 819         if ((bhslr->bhslr_flags & BHSLR_FLAGS_TRANSIT) == 0) {
 820                 login_send_error(request, 0x02, 0x00);
 821                 log_errx(1, "got no \"T\" flag after answering AuthMethod");
 822         }
 823
 824         log_debugx("got state transition request");
 825         response = login_new_response(request);
 826         pdu_delete(request);
 827         login_set_nsg(response, BHSLR_STAGE_OPERATIONAL_NEGOTIATION);
 828         pdu_send(response);
 829         pdu_delete(response);
 830
 831         login_negotiate(conn, NULL);
 832 }
 833
 834 void
 835 login(struct connection *conn)
 836 {
 837         struct pdu *request, *response;
 838         struct iscsi_bhs_login_request *bhslr;
 839         struct keys *request_keys, *response_keys;
 840         struct auth_group *ag;
 841         struct portal_group *pg;
 842         const char *initiator_name, *initiator_alias, *session_type,
 843             *target_name, *auth_method;
 844         bool redirected, fail, trans;
 845
 846         /*
 847          * Handle the initial Login Request - figure out required authentication
 848          * method and either transition to the next phase, if no authentication
 849          * is required, or call appropriate authentication code.
 850          */
 851         log_debugx("beginning Login Phase; waiting for Login PDU");
 852         request = login_receive(conn, true);
 853         bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs;
 854         if (bhslr->bhslr_tsih != 0) {
 855                 login_send_error(request, 0x02, 0x0a);
 856                 log_errx(1, "received Login PDU with non-zero TSIH");
 857         }
 858
 859         pg = conn->conn_portal->p_portal_group;
 860
 861         memcpy(conn->conn_initiator_isid, bhslr->bhslr_isid,
 862             sizeof(conn->conn_initiator_isid));
 863
 864         /*
 865          * XXX: Implement the C flag some day.
 866          */
 867         request_keys = keys_new();
 868         keys_load(request_keys, request);
 869
 870         assert(conn->conn_initiator_name == NULL);
 871         initiator_name = keys_find(request_keys, "InitiatorName");
 872         if (initiator_name == NULL) {
 873                 login_send_error(request, 0x02, 0x07);
 874                 log_errx(1, "received Login PDU without InitiatorName");
 875         }
 876         if (valid_iscsi_name(initiator_name) == false) {
 877                 login_send_error(request, 0x02, 0x00);
 878                 log_errx(1, "received Login PDU with invalid InitiatorName");
 879         }
 880         conn->conn_initiator_name = checked_strdup(initiator_name);
 881         log_set_peer_name(conn->conn_initiator_name);
 882         setproctitle("%s (%s)", conn->conn_initiator_addr, conn->conn_initiator_name);
 883
 884         redirected = login_portal_redirect(conn, request);
 885         if (redirected) {
 886                 log_debugx("initiator redirected; exiting");
 887                 exit(0);
 888         }
 889
 890         initiator_alias = keys_find(request_keys, "InitiatorAlias");
 891         if (initiator_alias != NULL)
 892                 conn->conn_initiator_alias = checked_strdup(initiator_alias);
 893
 894         assert(conn->conn_session_type == CONN_SESSION_TYPE_NONE);
 895         session_type = keys_find(request_keys, "SessionType");
 896         if (session_type != NULL) {
 897                 if (strcmp(session_type, "Normal") == 0) {
 898                         conn->conn_session_type = CONN_SESSION_TYPE_NORMAL;
 899                 } else if (strcmp(session_type, "Discovery") == 0) {
 900                         conn->conn_session_type = CONN_SESSION_TYPE_DISCOVERY;
 901                 } else {
 902                         login_send_error(request, 0x02, 0x00);
 903                         log_errx(1, "received Login PDU with invalid "
 904                             "SessionType \"%s\"", session_type);
 905                 }
 906         } else
 907                 conn->conn_session_type = CONN_SESSION_TYPE_NORMAL;
 908
 909         assert(conn->conn_target == NULL);
 910         if (conn->conn_session_type == CONN_SESSION_TYPE_NORMAL) {
 911                 target_name = keys_find(request_keys, "TargetName");
 912                 if (target_name == NULL) {
 913                         login_send_error(request, 0x02, 0x07);
 914                         log_errx(1, "received Login PDU without TargetName");
 915                 }
 916
 917                 conn->conn_port = port_find_in_pg(pg, target_name);
 918                 if (conn->conn_port == NULL) {
 919                         login_send_error(request, 0x02, 0x03);
 920                         log_errx(1, "requested target \"%s\" not found",
 921                             target_name);
 922                 }
 923                 conn->conn_target = conn->conn_port->p_target;
 924         }
 925
 926         /*
 927          * At this point we know what kind of authentication we need.
 928          */
 929         if (conn->conn_session_type == CONN_SESSION_TYPE_NORMAL) {
 930                 ag = conn->conn_port->p_auth_group;
 931                 if (ag == NULL)
 932                         ag = conn->conn_target->t_auth_group;
 933                 if (ag->ag_name != NULL) {
 934                         log_debugx("initiator requests to connect "
 935                             "to target \"%s\"; auth-group \"%s\"",
 936                             conn->conn_target->t_name,
 937                             ag->ag_name);
 938                 } else {
 939                         log_debugx("initiator requests to connect "
 940                             "to target \"%s\"", conn->conn_target->t_name);
 941                 }
 942         } else {
 943                 assert(conn->conn_session_type == CONN_SESSION_TYPE_DISCOVERY);
 944                 ag = pg->pg_discovery_auth_group;
 945                 if (ag->ag_name != NULL) {
 946                         log_debugx("initiator requests "
 947                             "discovery session; auth-group \"%s\"", ag->ag_name);
 948                 } else {
 949                         log_debugx("initiator requests discovery session");
 950                 }
 951         }
 952
 953         if (ag->ag_type == AG_TYPE_DENY) {
 954                 login_send_error(request, 0x02, 0x01);
 955                 log_errx(1, "auth-type is \"deny\"");
 956         }
 957
 958         if (ag->ag_type == AG_TYPE_UNKNOWN) {
 959                 /*
 960                  * This can happen with empty auth-group.
 961                  */
 962                 login_send_error(request, 0x02, 0x01);
 963                 log_errx(1, "auth-type not set, denying access");
 964         }
 965
 966         /*
 967          * Enforce initiator-name and initiator-portal.
 968          */
 969         if (auth_name_check(ag, initiator_name) != 0) {
 970                 login_send_error(request, 0x02, 0x02);
 971                 log_errx(1, "initiator does not match allowed initiator names");
 972         }
 973
 974         if (auth_portal_check(ag, &conn->conn_initiator_sa) != 0) {
 975                 login_send_error(request, 0x02, 0x02);
 976                 log_errx(1, "initiator does not match allowed "
 977                     "initiator portals");
 978         }
 979
 980         /*
 981          * Let's see if the initiator intends to do any kind of authentication
 982          * at all.
 983          */
 984         if (login_csg(request) == BHSLR_STAGE_OPERATIONAL_NEGOTIATION) {
 985                 if (ag->ag_type != AG_TYPE_NO_AUTHENTICATION) {
 986                         login_send_error(request, 0x02, 0x01);
 987                         log_errx(1, "initiator skipped the authentication, "
 988                             "but authentication is required");
 989                 }
 990
 991                 keys_delete(request_keys);
 992
 993                 log_debugx("initiator skipped the authentication, "
 994                     "and we don't need it; proceeding with negotiation");
 995                 login_negotiate(conn, request);
 996                 return;
 997         }
 998
 999         fail = false;
1000         response = login_new_response(request);
1001         response_keys = keys_new();
1002         trans = (bhslr->bhslr_flags & BHSLR_FLAGS_TRANSIT) != 0;
1003         auth_method = keys_find(request_keys, "AuthMethod");
1004         if (ag->ag_type == AG_TYPE_NO_AUTHENTICATION) {
1005                 log_debugx("authentication not required");
1006                 if (auth_method == NULL ||
1007                     login_list_contains(auth_method, "None")) {
1008                         keys_add(response_keys, "AuthMethod", "None");
1009                 } else {
1010                         log_warnx("initiator requests "
1011                             "AuthMethod \"%s\" instead of \"None\"",
1012                             auth_method);
1013                         keys_add(response_keys, "AuthMethod", "Reject");
1014                 }
1015                 if (trans)
1016                         login_set_nsg(response, BHSLR_STAGE_OPERATIONAL_NEGOTIATION);
1017         } else {
1018                 log_debugx("CHAP authentication required");
1019                 if (auth_method == NULL ||
1020                     login_list_contains(auth_method, "CHAP")) {
1021                         keys_add(response_keys, "AuthMethod", "CHAP");
1022                 } else {
1023                         log_warnx("initiator requests unsupported "
1024                             "AuthMethod \"%s\" instead of \"CHAP\"",
1025                             auth_method);
1026                         keys_add(response_keys, "AuthMethod", "Reject");
1027                         fail = true;
1028                 }
1029         }
1030         if (conn->conn_session_type == CONN_SESSION_TYPE_NORMAL) {
1031                 if (conn->conn_target->t_alias != NULL)
1032                         keys_add(response_keys,
1033                             "TargetAlias", conn->conn_target->t_alias);
1034                 keys_add_int(response_keys,
1035                     "TargetPortalGroupTag", pg->pg_tag);
1036         }
1037         keys_save(response_keys, response);
1038
1039         pdu_send(response);
1040         pdu_delete(response);
1041         keys_delete(response_keys);
1042         pdu_delete(request);
1043         keys_delete(request_keys);
1044
1045         if (fail) {
1046                 log_debugx("sent reject for AuthMethod; exiting");
1047                 exit(1);
1048         }
1049
1050         if (ag->ag_type != AG_TYPE_NO_AUTHENTICATION) {
1051                 login_chap(conn, ag);
1052                 login_negotiate(conn, NULL);
1053         } else if (trans) {
1054                 login_negotiate(conn, NULL);
1055         } else {
1056                 login_wait_transition(conn);
1057         }
1058 }