usr.sbin/ctld/login.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
   3  *
   4  * Copyright (c) 2012 The FreeBSD Foundation
   5  * All rights reserved.
   6  *
   7  * This software was developed by Edward Tomasz Napierala under sponsorship
   8  * from the FreeBSD Foundation.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  *
  31  */
  32
  33 #include <sys/cdefs.h>
  34 __FBSDID("$FreeBSD$");
  35
  36 #include <assert.h>
  37 #include <stdbool.h>
  38 #include <stdlib.h>
  39 #include <string.h>
  40 #include <unistd.h>
  41 #include <netinet/in.h>
  42
  43 #include "ctld.h"
  44 #include "iscsi_proto.h"
  45
  46 static void login_send_error(struct pdu *request,
  47     char class, char detail);
  48
  49 static void
  50 login_set_nsg(struct pdu *response, int nsg)
  51 {
  52         struct iscsi_bhs_login_response *bhslr;
  53
  54         assert(nsg == BHSLR_STAGE_SECURITY_NEGOTIATION ||
  55             nsg == BHSLR_STAGE_OPERATIONAL_NEGOTIATION ||
  56             nsg == BHSLR_STAGE_FULL_FEATURE_PHASE);
  57
  58         bhslr = (struct iscsi_bhs_login_response *)response->pdu_bhs;
  59
  60         bhslr->bhslr_flags &= 0xFC;
  61         bhslr->bhslr_flags |= nsg;
  62         bhslr->bhslr_flags |= BHSLR_FLAGS_TRANSIT;
  63 }
  64
  65 static int
  66 login_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
  75 static void
  76 login_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
  90 static struct pdu *
  91 login_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 (initial == false &&
 132             ISCSI_SNLT(ntohl(bhslr->bhslr_cmdsn), conn->conn_cmdsn)) {
 133                 login_send_error(request, 0x02, 0x00);
 134                 log_errx(1, "received Login PDU with decreasing CmdSN: "
 135                     "was %u, is %u", conn->conn_cmdsn,
 136                     ntohl(bhslr->bhslr_cmdsn));
 137         }
 138         if (initial == false &&
 139             ntohl(bhslr->bhslr_expstatsn) != conn->conn_statsn) {
 140                 login_send_error(request, 0x02, 0x00);
 141                 log_errx(1, "received Login PDU with wrong ExpStatSN: "
 142                     "is %u, should be %u", ntohl(bhslr->bhslr_expstatsn),
 143                     conn->conn_statsn);
 144         }
 145         conn->conn_cmdsn = ntohl(bhslr->bhslr_cmdsn);
 146
 147         return (request);
 148 }
 149
 150 static struct pdu *
 151 login_new_response(struct pdu *request)
 152 {
 153         struct pdu *response;
 154         struct connection *conn;
 155         struct iscsi_bhs_login_request *bhslr;
 156         struct iscsi_bhs_login_response *bhslr2;
 157
 158         bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs;
 159         conn = request->pdu_connection;
 160
 161         response = pdu_new_response(request);
 162         bhslr2 = (struct iscsi_bhs_login_response *)response->pdu_bhs;
 163         bhslr2->bhslr_opcode = ISCSI_BHS_OPCODE_LOGIN_RESPONSE;
 164         login_set_csg(response, BHSLR_STAGE_SECURITY_NEGOTIATION);
 165         memcpy(bhslr2->bhslr_isid,
 166             bhslr->bhslr_isid, sizeof(bhslr2->bhslr_isid));
 167         bhslr2->bhslr_initiator_task_tag = bhslr->bhslr_initiator_task_tag;
 168         bhslr2->bhslr_statsn = htonl(conn->conn_statsn++);
 169         bhslr2->bhslr_expcmdsn = htonl(conn->conn_cmdsn);
 170         bhslr2->bhslr_maxcmdsn = htonl(conn->conn_cmdsn);
 171
 172         return (response);
 173 }
 174
 175 static void
 176 login_send_error(struct pdu *request, char class, char detail)
 177 {
 178         struct pdu *response;
 179         struct iscsi_bhs_login_response *bhslr2;
 180
 181         log_debugx("sending Login Response PDU with failure class 0x%x/0x%x; "
 182             "see next line for reason", class, detail);
 183         response = login_new_response(request);
 184         bhslr2 = (struct iscsi_bhs_login_response *)response->pdu_bhs;
 185         bhslr2->bhslr_status_class = class;
 186         bhslr2->bhslr_status_detail = detail;
 187
 188         pdu_send(response);
 189         pdu_delete(response);
 190 }
 191
 192 static int
 193 login_list_contains(const char *list, const char *what)
 194 {
 195         char *tofree, *str, *token;
 196
 197         tofree = str = checked_strdup(list);
 198
 199         while ((token = strsep(&str, ",")) != NULL) {
 200                 if (strcmp(token, what) == 0) {
 201                         free(tofree);
 202                         return (1);
 203                 }
 204         }
 205         free(tofree);
 206         return (0);
 207 }
 208
 209 static int
 210 login_list_prefers(const char *list,
 211     const char *choice1, const char *choice2)
 212 {
 213         char *tofree, *str, *token;
 214
 215         tofree = str = checked_strdup(list);
 216
 217         while ((token = strsep(&str, ",")) != NULL) {
 218                 if (strcmp(token, choice1) == 0) {
 219                         free(tofree);
 220                         return (1);
 221                 }
 222                 if (strcmp(token, choice2) == 0) {
 223                         free(tofree);
 224                         return (2);
 225                 }
 226         }
 227         free(tofree);
 228         return (-1);
 229 }
 230
 231 static struct pdu *
 232 login_receive_chap_a(struct connection *conn)
 233 {
 234         struct pdu *request;
 235         struct keys *request_keys;
 236         const char *chap_a;
 237
 238         request = login_receive(conn, false);
 239         request_keys = keys_new();
 240         keys_load(request_keys, request);
 241
 242         chap_a = keys_find(request_keys, "CHAP_A");
 243         if (chap_a == NULL) {
 244                 login_send_error(request, 0x02, 0x07);
 245                 log_errx(1, "received CHAP Login PDU without CHAP_A");
 246         }
 247         if (login_list_contains(chap_a, "5") == 0) {
 248                 login_send_error(request, 0x02, 0x01);
 249                 log_errx(1, "received CHAP Login PDU with unsupported CHAP_A "
 250                     "\"%s\"", chap_a);
 251         }
 252         keys_delete(request_keys);
 253
 254         return (request);
 255 }
 256
 257 static void
 258 login_send_chap_c(struct pdu *request, struct chap *chap)
 259 {
 260         struct pdu *response;
 261         struct keys *response_keys;
 262         char *chap_c, *chap_i;
 263
 264         chap_c = chap_get_challenge(chap);
 265         chap_i = chap_get_id(chap);
 266
 267         response = login_new_response(request);
 268         response_keys = keys_new();
 269         keys_add(response_keys, "CHAP_A", "5");
 270         keys_add(response_keys, "CHAP_I", chap_i);
 271         keys_add(response_keys, "CHAP_C", chap_c);
 272         free(chap_i);
 273         free(chap_c);
 274         keys_save(response_keys, response);
 275         pdu_send(response);
 276         pdu_delete(response);
 277         keys_delete(response_keys);
 278 }
 279
 280 static struct pdu *
 281 login_receive_chap_r(struct connection *conn, struct auth_group *ag,
 282     struct chap *chap, const struct auth **authp)
 283 {
 284         struct pdu *request;
 285         struct keys *request_keys;
 286         const char *chap_n, *chap_r;
 287         const struct auth *auth;
 288         int error;
 289
 290         request = login_receive(conn, false);
 291         request_keys = keys_new();
 292         keys_load(request_keys, request);
 293
 294         chap_n = keys_find(request_keys, "CHAP_N");
 295         if (chap_n == NULL) {
 296                 login_send_error(request, 0x02, 0x07);
 297                 log_errx(1, "received CHAP Login PDU without CHAP_N");
 298         }
 299         chap_r = keys_find(request_keys, "CHAP_R");
 300         if (chap_r == NULL) {
 301                 login_send_error(request, 0x02, 0x07);
 302                 log_errx(1, "received CHAP Login PDU without CHAP_R");
 303         }
 304         error = chap_receive(chap, chap_r);
 305         if (error != 0) {
 306                 login_send_error(request, 0x02, 0x07);
 307                 log_errx(1, "received CHAP Login PDU with malformed CHAP_R");
 308         }
 309
 310         /*
 311          * Verify the response.
 312          */
 313         assert(ag->ag_type == AG_TYPE_CHAP ||
 314             ag->ag_type == AG_TYPE_CHAP_MUTUAL);
 315         auth = auth_find(ag, chap_n);
 316         if (auth == NULL) {
 317                 login_send_error(request, 0x02, 0x01);
 318                 log_errx(1, "received CHAP Login with invalid user \"%s\"",
 319                     chap_n);
 320         }
 321
 322         assert(auth->a_secret != NULL);
 323         assert(strlen(auth->a_secret) > 0);
 324
 325         error = chap_authenticate(chap, auth->a_secret);
 326         if (error != 0) {
 327                 login_send_error(request, 0x02, 0x01);
 328                 log_errx(1, "CHAP authentication failed for user \"%s\"",
 329                     auth->a_user);
 330         }
 331
 332         keys_delete(request_keys);
 333
 334         *authp = auth;
 335         return (request);
 336 }
 337
 338 static void
 339 login_send_chap_success(struct pdu *request,
 340     const struct auth *auth)
 341 {
 342         struct pdu *response;
 343         struct keys *request_keys, *response_keys;
 344         struct rchap *rchap;
 345         const char *chap_i, *chap_c;
 346         char *chap_r;
 347         int error;
 348
 349         response = login_new_response(request);
 350         login_set_nsg(response, BHSLR_STAGE_OPERATIONAL_NEGOTIATION);
 351
 352         /*
 353          * Actually, one more thing: mutual authentication.
 354          */
 355         request_keys = keys_new();
 356         keys_load(request_keys, request);
 357         chap_i = keys_find(request_keys, "CHAP_I");
 358         chap_c = keys_find(request_keys, "CHAP_C");
 359         if (chap_i != NULL || chap_c != NULL) {
 360                 if (chap_i == NULL) {
 361                         login_send_error(request, 0x02, 0x07);
 362                         log_errx(1, "initiator requested target "
 363                             "authentication, but didn't send CHAP_I");
 364                 }
 365                 if (chap_c == NULL) {
 366                         login_send_error(request, 0x02, 0x07);
 367                         log_errx(1, "initiator requested target "
 368                             "authentication, but didn't send CHAP_C");
 369                 }
 370                 if (auth->a_auth_group->ag_type != AG_TYPE_CHAP_MUTUAL) {
 371                         login_send_error(request, 0x02, 0x01);
 372                         log_errx(1, "initiator requests target authentication "
 373                             "for user \"%s\", but mutual user/secret "
 374                             "is not set", auth->a_user);
 375                 }
 376
 377                 log_debugx("performing mutual authentication as user \"%s\"",
 378                     auth->a_mutual_user);
 379
 380                 rchap = rchap_new(auth->a_mutual_secret);
 381                 error = rchap_receive(rchap, chap_i, chap_c);
 382                 if (error != 0) {
 383                         login_send_error(request, 0x02, 0x07);
 384                         log_errx(1, "received CHAP Login PDU with malformed "
 385                             "CHAP_I or CHAP_C");
 386                 }
 387                 chap_r = rchap_get_response(rchap);
 388                 rchap_delete(rchap);
 389                 response_keys = keys_new();
 390                 keys_add(response_keys, "CHAP_N", auth->a_mutual_user);
 391                 keys_add(response_keys, "CHAP_R", chap_r);
 392                 free(chap_r);
 393                 keys_save(response_keys, response);
 394                 keys_delete(response_keys);
 395         } else {
 396                 log_debugx("initiator did not request target authentication");
 397         }
 398
 399         keys_delete(request_keys);
 400         pdu_send(response);
 401         pdu_delete(response);
 402 }
 403
 404 static void
 405 login_chap(struct connection *conn, struct auth_group *ag)
 406 {
 407         const struct auth *auth;
 408         struct chap *chap;
 409         struct pdu *request;
 410
 411         /*
 412          * Receive CHAP_A PDU.
 413          */
 414         log_debugx("beginning CHAP authentication; waiting for CHAP_A");
 415         request = login_receive_chap_a(conn);
 416
 417         /*
 418          * Generate the challenge.
 419          */
 420         chap = chap_new();
 421
 422         /*
 423          * Send the challenge.
 424          */
 425         log_debugx("sending CHAP_C, binary challenge size is %zd bytes",
 426             sizeof(chap->chap_challenge));
 427         login_send_chap_c(request, chap);
 428         pdu_delete(request);
 429
 430         /*
 431          * Receive CHAP_N/CHAP_R PDU and authenticate.
 432          */
 433         log_debugx("waiting for CHAP_N/CHAP_R");
 434         request = login_receive_chap_r(conn, ag, chap, &auth);
 435
 436         /*
 437          * Yay, authentication succeeded!
 438          */
 439         log_debugx("authentication succeeded for user \"%s\"; "
 440             "transitioning to operational parameter negotiation", auth->a_user);
 441         login_send_chap_success(request, auth);
 442         pdu_delete(request);
 443
 444         /*
 445          * Leave username and CHAP information for discovery().
 446          */
 447         conn->conn_user = auth->a_user;
 448         conn->conn_chap = chap;
 449 }
 450
 451 static void
 452 login_negotiate_key(struct pdu *request, const char *name,
 453     const char *value, bool skipped_security, struct keys *response_keys)
 454 {
 455         int which;
 456         size_t tmp;
 457         struct connection *conn;
 458
 459         conn = request->pdu_connection;
 460
 461         if (strcmp(name, "InitiatorName") == 0) {
 462                 if (!skipped_security)
 463                         log_errx(1, "initiator resent InitiatorName");
 464         } else if (strcmp(name, "SessionType") == 0) {
 465                 if (!skipped_security)
 466                         log_errx(1, "initiator resent SessionType");
 467         } else if (strcmp(name, "TargetName") == 0) {
 468                 if (!skipped_security)
 469                         log_errx(1, "initiator resent TargetName");
 470         } else if (strcmp(name, "InitiatorAlias") == 0) {
 471                 if (conn->conn_initiator_alias != NULL)
 472                         free(conn->conn_initiator_alias);
 473                 conn->conn_initiator_alias = checked_strdup(value);
 474         } else if (strcmp(value, "Irrelevant") == 0) {
 475                 /* Ignore. */
 476         } else if (strcmp(name, "HeaderDigest") == 0) {
 477                 /*
 478                  * We don't handle digests for discovery sessions.
 479                  */
 480                 if (conn->conn_session_type == CONN_SESSION_TYPE_DISCOVERY) {
 481                         log_debugx("discovery session; digests disabled");
 482                         keys_add(response_keys, name, "None");
 483                         return;
 484                 }
 485
 486                 which = login_list_prefers(value, "CRC32C", "None");
 487                 switch (which) {
 488                 case 1:
 489                         log_debugx("initiator prefers CRC32C "
 490                             "for header digest; we'll use it");
 491                         conn->conn_header_digest = CONN_DIGEST_CRC32C;
 492                         keys_add(response_keys, name, "CRC32C");
 493                         break;
 494                 case 2:
 495                         log_debugx("initiator prefers not to do "
 496                             "header digest; we'll comply");
 497                         keys_add(response_keys, name, "None");
 498                         break;
 499                 default:
 500                         log_warnx("initiator sent unrecognized "
 501                             "HeaderDigest value \"%s\"; will use None", value);
 502                         keys_add(response_keys, name, "None");
 503                         break;
 504                 }
 505         } else if (strcmp(name, "DataDigest") == 0) {
 506                 if (conn->conn_session_type == CONN_SESSION_TYPE_DISCOVERY) {
 507                         log_debugx("discovery session; digests disabled");
 508                         keys_add(response_keys, name, "None");
 509                         return;
 510                 }
 511
 512                 which = login_list_prefers(value, "CRC32C", "None");
 513                 switch (which) {
 514                 case 1:
 515                         log_debugx("initiator prefers CRC32C "
 516                             "for data digest; we'll use it");
 517                         conn->conn_data_digest = CONN_DIGEST_CRC32C;
 518                         keys_add(response_keys, name, "CRC32C");
 519                         break;
 520                 case 2:
 521                         log_debugx("initiator prefers not to do "
 522                             "data digest; we'll comply");
 523                         keys_add(response_keys, name, "None");
 524                         break;
 525                 default:
 526                         log_warnx("initiator sent unrecognized "
 527                             "DataDigest value \"%s\"; will use None", value);
 528                         keys_add(response_keys, name, "None");
 529                         break;
 530                 }
 531         } else if (strcmp(name, "MaxConnections") == 0) {
 532                 keys_add(response_keys, name, "1");
 533         } else if (strcmp(name, "InitialR2T") == 0) {
 534                 keys_add(response_keys, name, "Yes");
 535         } else if (strcmp(name, "ImmediateData") == 0) {
 536                 if (conn->conn_session_type == CONN_SESSION_TYPE_DISCOVERY) {
 537                         log_debugx("discovery session; ImmediateData irrelevant");
 538                         keys_add(response_keys, name, "Irrelevant");
 539                 } else {
 540                         if (strcmp(value, "Yes") == 0) {
 541                                 conn->conn_immediate_data = true;
 542                                 keys_add(response_keys, name, "Yes");
 543                         } else {
 544                                 conn->conn_immediate_data = false;
 545                                 keys_add(response_keys, name, "No");
 546                         }
 547                 }
 548         } else if (strcmp(name, "MaxRecvDataSegmentLength") == 0) {
 549                 tmp = strtoul(value, NULL, 10);
 550                 if (tmp <= 0) {
 551                         login_send_error(request, 0x02, 0x00);
 552                         log_errx(1, "received invalid "
 553                             "MaxRecvDataSegmentLength");
 554                 }
 555                 if (tmp > conn->conn_data_segment_limit) {
 556                         log_debugx("capping MaxRecvDataSegmentLength "
 557                             "from %zd to %zd", tmp, conn->conn_data_segment_limit);
 558                         tmp = conn->conn_data_segment_limit;
 559                 }
 560                 conn->conn_max_data_segment_length = tmp;
 561                 keys_add_int(response_keys, name, conn->conn_data_segment_limit);
 562         } else if (strcmp(name, "MaxBurstLength") == 0) {
 563                 tmp = strtoul(value, NULL, 10);
 564                 if (tmp <= 0) {
 565                         login_send_error(request, 0x02, 0x00);
 566                         log_errx(1, "received invalid MaxBurstLength");
 567                 }
 568                 if (tmp > MAX_BURST_LENGTH) {
 569                         log_debugx("capping MaxBurstLength from %zd to %d",
 570                             tmp, MAX_BURST_LENGTH);
 571                         tmp = MAX_BURST_LENGTH;
 572                 }
 573                 conn->conn_max_burst_length = tmp;
 574                 keys_add_int(response_keys, name, tmp);
 575         } else if (strcmp(name, "FirstBurstLength") == 0) {
 576                 tmp = strtoul(value, NULL, 10);
 577                 if (tmp <= 0) {
 578                         login_send_error(request, 0x02, 0x00);
 579                         log_errx(1, "received invalid FirstBurstLength");
 580                 }
 581                 if (tmp > FIRST_BURST_LENGTH) {
 582                         log_debugx("capping FirstBurstLength from %zd to %d",
 583                             tmp, FIRST_BURST_LENGTH);
 584                         tmp = FIRST_BURST_LENGTH;
 585                 }
 586                 conn->conn_first_burst_length = tmp;
 587                 keys_add_int(response_keys, name, tmp);
 588         } else if (strcmp(name, "DefaultTime2Wait") == 0) {
 589                 keys_add(response_keys, name, value);
 590         } else if (strcmp(name, "DefaultTime2Retain") == 0) {
 591                 keys_add(response_keys, name, "0");
 592         } else if (strcmp(name, "MaxOutstandingR2T") == 0) {
 593                 keys_add(response_keys, name, "1");
 594         } else if (strcmp(name, "DataPDUInOrder") == 0) {
 595                 keys_add(response_keys, name, "Yes");
 596         } else if (strcmp(name, "DataSequenceInOrder") == 0) {
 597                 keys_add(response_keys, name, "Yes");
 598         } else if (strcmp(name, "ErrorRecoveryLevel") == 0) {
 599                 keys_add(response_keys, name, "0");
 600         } else if (strcmp(name, "OFMarker") == 0) {
 601                 keys_add(response_keys, name, "No");
 602         } else if (strcmp(name, "IFMarker") == 0) {
 603                 keys_add(response_keys, name, "No");
 604         } else if (strcmp(name, "iSCSIProtocolLevel") == 0) {
 605                 tmp = strtoul(value, NULL, 10);
 606                 if (tmp > 2)
 607                         tmp = 2;
 608                 keys_add_int(response_keys, name, tmp);
 609         } else {
 610                 log_debugx("unknown key \"%s\"; responding "
 611                     "with NotUnderstood", name);
 612                 keys_add(response_keys, name, "NotUnderstood");
 613         }
 614 }
 615
 616 static void
 617 login_redirect(struct pdu *request, const char *target_address)
 618 {
 619         struct pdu *response;
 620         struct iscsi_bhs_login_response *bhslr2;
 621         struct keys *response_keys;
 622
 623         response = login_new_response(request);
 624         login_set_csg(response, login_csg(request));
 625         bhslr2 = (struct iscsi_bhs_login_response *)response->pdu_bhs;
 626         bhslr2->bhslr_status_class = 0x01;
 627         bhslr2->bhslr_status_detail = 0x01;
 628
 629         response_keys = keys_new();
 630         keys_add(response_keys, "TargetAddress", target_address);
 631
 632         keys_save(response_keys, response);
 633         pdu_send(response);
 634         pdu_delete(response);
 635         keys_delete(response_keys);
 636 }
 637
 638 static bool
 639 login_portal_redirect(struct connection *conn, struct pdu *request)
 640 {
 641         const struct portal_group *pg;
 642
 643         pg = conn->conn_portal->p_portal_group;
 644         if (pg->pg_redirection == NULL)
 645                 return (false);
 646
 647         log_debugx("portal-group \"%s\" configured to redirect to %s",
 648             pg->pg_name, pg->pg_redirection);
 649         login_redirect(request, pg->pg_redirection);
 650
 651         return (true);
 652 }
 653
 654 static bool
 655 login_target_redirect(struct connection *conn, struct pdu *request)
 656 {
 657         const char *target_address;
 658
 659         assert(conn->conn_portal->p_portal_group->pg_redirection == NULL);
 660
 661         if (conn->conn_target == NULL)
 662                 return (false);
 663
 664         target_address = conn->conn_target->t_redirection;
 665         if (target_address == NULL)
 666                 return (false);
 667
 668         log_debugx("target \"%s\" configured to redirect to %s",
 669           conn->conn_target->t_name, target_address);
 670         login_redirect(request, target_address);
 671
 672         return (true);
 673 }
 674
 675 static void
 676 login_negotiate(struct connection *conn, struct pdu *request)
 677 {
 678         struct pdu *response;
 679         struct iscsi_bhs_login_response *bhslr2;
 680         struct keys *request_keys, *response_keys;
 681         int i;
 682         bool redirected, skipped_security;
 683
 684         if (conn->conn_session_type == CONN_SESSION_TYPE_NORMAL) {
 685                 /*
 686                  * Query the kernel for MaxDataSegmentLength it can handle.
 687                  * In case of offload, it depends on hardware capabilities.
 688                  */
 689                 assert(conn->conn_target != NULL);
 690                 kernel_limits(conn->conn_portal->p_portal_group->pg_offload,
 691                     &conn->conn_data_segment_limit);
 692         } else {
 693                 conn->conn_data_segment_limit = MAX_DATA_SEGMENT_LENGTH;
 694         }
 695
 696         if (request == NULL) {
 697                 log_debugx("beginning operational parameter negotiation; "
 698                     "waiting for Login PDU");
 699                 request = login_receive(conn, false);
 700                 skipped_security = false;
 701         } else
 702                 skipped_security = true;
 703
 704         /*
 705          * RFC 3720, 10.13.5.  Status-Class and Status-Detail, says
 706          * the redirection SHOULD be accepted by the initiator before
 707          * authentication, but MUST be be accepted afterwards; that's
 708          * why we're doing it here and not earlier.
 709          */
 710         redirected = login_target_redirect(conn, request);
 711         if (redirected) {
 712                 log_debugx("initiator redirected; exiting");
 713                 exit(0);
 714         }
 715
 716         request_keys = keys_new();
 717         keys_load(request_keys, request);
 718
 719         response = login_new_response(request);
 720         bhslr2 = (struct iscsi_bhs_login_response *)response->pdu_bhs;
 721         bhslr2->bhslr_tsih = htons(0xbadd);
 722         login_set_csg(response, BHSLR_STAGE_OPERATIONAL_NEGOTIATION);
 723         login_set_nsg(response, BHSLR_STAGE_FULL_FEATURE_PHASE);
 724         response_keys = keys_new();
 725
 726         if (skipped_security &&
 727             conn->conn_session_type == CONN_SESSION_TYPE_NORMAL) {
 728                 if (conn->conn_target->t_alias != NULL)
 729                         keys_add(response_keys,
 730                             "TargetAlias", conn->conn_target->t_alias);
 731                 keys_add_int(response_keys, "TargetPortalGroupTag",
 732                     conn->conn_portal->p_portal_group->pg_tag);
 733         }
 734
 735         for (i = 0; i < KEYS_MAX; i++) {
 736                 if (request_keys->keys_names[i] == NULL)
 737                         break;
 738
 739                 login_negotiate_key(request, request_keys->keys_names[i],
 740                     request_keys->keys_values[i], skipped_security,
 741                     response_keys);
 742         }
 743
 744         log_debugx("operational parameter negotiation done; "
 745             "transitioning to Full Feature Phase");
 746
 747         keys_save(response_keys, response);
 748         pdu_send(response);
 749         pdu_delete(response);
 750         keys_delete(response_keys);
 751         pdu_delete(request);
 752         keys_delete(request_keys);
 753 }
 754
 755 static void
 756 login_wait_transition(struct connection *conn)
 757 {
 758         struct pdu *request, *response;
 759         struct iscsi_bhs_login_request *bhslr;
 760
 761         log_debugx("waiting for state transition request");
 762         request = login_receive(conn, false);
 763         bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs;
 764         if ((bhslr->bhslr_flags & BHSLR_FLAGS_TRANSIT) == 0) {
 765                 login_send_error(request, 0x02, 0x00);
 766                 log_errx(1, "got no \"T\" flag after answering AuthMethod");
 767         }
 768
 769         log_debugx("got state transition request");
 770         response = login_new_response(request);
 771         pdu_delete(request);
 772         login_set_nsg(response, BHSLR_STAGE_OPERATIONAL_NEGOTIATION);
 773         pdu_send(response);
 774         pdu_delete(response);
 775
 776         login_negotiate(conn, NULL);
 777 }
 778
 779 void
 780 login(struct connection *conn)
 781 {
 782         struct pdu *request, *response;
 783         struct iscsi_bhs_login_request *bhslr;
 784         struct keys *request_keys, *response_keys;
 785         struct auth_group *ag;
 786         struct portal_group *pg;
 787         const char *initiator_name, *initiator_alias, *session_type,
 788             *target_name, *auth_method;
 789         bool redirected, fail, trans;
 790
 791         /*
 792          * Handle the initial Login Request - figure out required authentication
 793          * method and either transition to the next phase, if no authentication
 794          * is required, or call appropriate authentication code.
 795          */
 796         log_debugx("beginning Login Phase; waiting for Login PDU");
 797         request = login_receive(conn, true);
 798         bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs;
 799         if (bhslr->bhslr_tsih != 0) {
 800                 login_send_error(request, 0x02, 0x0a);
 801                 log_errx(1, "received Login PDU with non-zero TSIH");
 802         }
 803
 804         pg = conn->conn_portal->p_portal_group;
 805
 806         memcpy(conn->conn_initiator_isid, bhslr->bhslr_isid,
 807             sizeof(conn->conn_initiator_isid));
 808
 809         /*
 810          * XXX: Implement the C flag some day.
 811          */
 812         request_keys = keys_new();
 813         keys_load(request_keys, request);
 814
 815         assert(conn->conn_initiator_name == NULL);
 816         initiator_name = keys_find(request_keys, "InitiatorName");
 817         if (initiator_name == NULL) {
 818                 login_send_error(request, 0x02, 0x07);
 819                 log_errx(1, "received Login PDU without InitiatorName");
 820         }
 821         if (valid_iscsi_name(initiator_name) == false) {
 822                 login_send_error(request, 0x02, 0x00);
 823                 log_errx(1, "received Login PDU with invalid InitiatorName");
 824         }
 825         conn->conn_initiator_name = checked_strdup(initiator_name);
 826         log_set_peer_name(conn->conn_initiator_name);
 827         setproctitle("%s (%s)", conn->conn_initiator_addr, conn->conn_initiator_name);
 828
 829         redirected = login_portal_redirect(conn, request);
 830         if (redirected) {
 831                 log_debugx("initiator redirected; exiting");
 832                 exit(0);
 833         }
 834
 835         initiator_alias = keys_find(request_keys, "InitiatorAlias");
 836         if (initiator_alias != NULL)
 837                 conn->conn_initiator_alias = checked_strdup(initiator_alias);
 838
 839         assert(conn->conn_session_type == CONN_SESSION_TYPE_NONE);
 840         session_type = keys_find(request_keys, "SessionType");
 841         if (session_type != NULL) {
 842                 if (strcmp(session_type, "Normal") == 0) {
 843                         conn->conn_session_type = CONN_SESSION_TYPE_NORMAL;
 844                 } else if (strcmp(session_type, "Discovery") == 0) {
 845                         conn->conn_session_type = CONN_SESSION_TYPE_DISCOVERY;
 846                 } else {
 847                         login_send_error(request, 0x02, 0x00);
 848                         log_errx(1, "received Login PDU with invalid "
 849                             "SessionType \"%s\"", session_type);
 850                 }
 851         } else
 852                 conn->conn_session_type = CONN_SESSION_TYPE_NORMAL;
 853
 854         assert(conn->conn_target == NULL);
 855         if (conn->conn_session_type == CONN_SESSION_TYPE_NORMAL) {
 856                 target_name = keys_find(request_keys, "TargetName");
 857                 if (target_name == NULL) {
 858                         login_send_error(request, 0x02, 0x07);
 859                         log_errx(1, "received Login PDU without TargetName");
 860                 }
 861
 862                 conn->conn_port = port_find_in_pg(pg, target_name);
 863                 if (conn->conn_port == NULL) {
 864                         login_send_error(request, 0x02, 0x03);
 865                         log_errx(1, "requested target \"%s\" not found",
 866                             target_name);
 867                 }
 868                 conn->conn_target = conn->conn_port->p_target;
 869         }
 870
 871         /*
 872          * At this point we know what kind of authentication we need.
 873          */
 874         if (conn->conn_session_type == CONN_SESSION_TYPE_NORMAL) {
 875                 ag = conn->conn_port->p_auth_group;
 876                 if (ag == NULL)
 877                         ag = conn->conn_target->t_auth_group;
 878                 if (ag->ag_name != NULL) {
 879                         log_debugx("initiator requests to connect "
 880                             "to target \"%s\"; auth-group \"%s\"",
 881                             conn->conn_target->t_name,
 882                             ag->ag_name);
 883                 } else {
 884                         log_debugx("initiator requests to connect "
 885                             "to target \"%s\"", conn->conn_target->t_name);
 886                 }
 887         } else {
 888                 assert(conn->conn_session_type == CONN_SESSION_TYPE_DISCOVERY);
 889                 ag = pg->pg_discovery_auth_group;
 890                 if (ag->ag_name != NULL) {
 891                         log_debugx("initiator requests "
 892                             "discovery session; auth-group \"%s\"", ag->ag_name);
 893                 } else {
 894                         log_debugx("initiator requests discovery session");
 895                 }
 896         }
 897
 898         if (ag->ag_type == AG_TYPE_DENY) {
 899                 login_send_error(request, 0x02, 0x01);
 900                 log_errx(1, "auth-type is \"deny\"");
 901         }
 902
 903         if (ag->ag_type == AG_TYPE_UNKNOWN) {
 904                 /*
 905                  * This can happen with empty auth-group.
 906                  */
 907                 login_send_error(request, 0x02, 0x01);
 908                 log_errx(1, "auth-type not set, denying access");
 909         }
 910
 911         /*
 912          * Enforce initiator-name and initiator-portal.
 913          */
 914         if (auth_name_check(ag, initiator_name) != 0) {
 915                 login_send_error(request, 0x02, 0x02);
 916                 log_errx(1, "initiator does not match allowed initiator names");
 917         }
 918
 919         if (auth_portal_check(ag, &conn->conn_initiator_sa) != 0) {
 920                 login_send_error(request, 0x02, 0x02);
 921                 log_errx(1, "initiator does not match allowed "
 922                     "initiator portals");
 923         }
 924
 925         /*
 926          * Let's see if the initiator intends to do any kind of authentication
 927          * at all.
 928          */
 929         if (login_csg(request) == BHSLR_STAGE_OPERATIONAL_NEGOTIATION) {
 930                 if (ag->ag_type != AG_TYPE_NO_AUTHENTICATION) {
 931                         login_send_error(request, 0x02, 0x01);
 932                         log_errx(1, "initiator skipped the authentication, "
 933                             "but authentication is required");
 934                 }
 935
 936                 keys_delete(request_keys);
 937
 938                 log_debugx("initiator skipped the authentication, "
 939                     "and we don't need it; proceeding with negotiation");
 940                 login_negotiate(conn, request);
 941                 return;
 942         }
 943
 944         fail = false;
 945         response = login_new_response(request);
 946         response_keys = keys_new();
 947         trans = (bhslr->bhslr_flags & BHSLR_FLAGS_TRANSIT) != 0;
 948         auth_method = keys_find(request_keys, "AuthMethod");
 949         if (ag->ag_type == AG_TYPE_NO_AUTHENTICATION) {
 950                 log_debugx("authentication not required");
 951                 if (auth_method == NULL ||
 952                     login_list_contains(auth_method, "None")) {
 953                         keys_add(response_keys, "AuthMethod", "None");
 954                 } else {
 955                         log_warnx("initiator requests "
 956                             "AuthMethod \"%s\" instead of \"None\"",
 957                             auth_method);
 958                         keys_add(response_keys, "AuthMethod", "Reject");
 959                 }
 960                 if (trans)
 961                         login_set_nsg(response, BHSLR_STAGE_OPERATIONAL_NEGOTIATION);
 962         } else {
 963                 log_debugx("CHAP authentication required");
 964                 if (auth_method == NULL ||
 965                     login_list_contains(auth_method, "CHAP")) {
 966                         keys_add(response_keys, "AuthMethod", "CHAP");
 967                 } else {
 968                         log_warnx("initiator requests unsupported "
 969                             "AuthMethod \"%s\" instead of \"CHAP\"",
 970                             auth_method);
 971                         keys_add(response_keys, "AuthMethod", "Reject");
 972                         fail = true;
 973                 }
 974         }
 975         if (conn->conn_session_type == CONN_SESSION_TYPE_NORMAL) {
 976                 if (conn->conn_target->t_alias != NULL)
 977                         keys_add(response_keys,
 978                             "TargetAlias", conn->conn_target->t_alias);
 979                 keys_add_int(response_keys,
 980                     "TargetPortalGroupTag", pg->pg_tag);
 981         }
 982         keys_save(response_keys, response);
 983
 984         pdu_send(response);
 985         pdu_delete(response);
 986         keys_delete(response_keys);
 987         pdu_delete(request);
 988         keys_delete(request_keys);
 989
 990         if (fail) {
 991                 log_debugx("sent reject for AuthMethod; exiting");
 992                 exit(1);
 993         }
 994
 995         if (ag->ag_type != AG_TYPE_NO_AUTHENTICATION) {
 996                 login_chap(conn, ag);
 997                 login_negotiate(conn, NULL);
 998         } else if (trans) {
 999                 login_negotiate(conn, NULL);
1000         } else {
1001                 login_wait_transition(conn);
1002         }
1003 }