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
 556                 /*
 557                  * MaxRecvDataSegmentLength is a direction-specific parameter.
 558                  * We'll limit our _send_ to what the initiator can handle but
 559                  * our MaxRecvDataSegmentLength is not influenced by the
 560                  * initiator in any way.
 561                  */
 562                 if ((int)tmp > conn->conn_max_send_data_segment_limit) {
 563                         log_debugx("capping MaxRecvDataSegmentLength "
 564                             "from %zd to %d", tmp,
 565                             conn->conn_max_send_data_segment_limit);
 566                         tmp = conn->conn_max_send_data_segment_limit;
 567                 }
 568                 conn->conn_max_send_data_segment_length = tmp;
 569                 conn->conn_max_recv_data_segment_length =
 570                     conn->conn_max_recv_data_segment_limit;
 571                 keys_add_int(response_keys, name,
 572                     conn->conn_max_recv_data_segment_length);
 573         } else if (strcmp(name, "MaxBurstLength") == 0) {
 574                 tmp = strtoul(value, NULL, 10);
 575                 if (tmp <= 0) {
 576                         login_send_error(request, 0x02, 0x00);
 577                         log_errx(1, "received invalid MaxBurstLength");
 578                 }
 579                 if ((int)tmp > conn->conn_max_burst_limit) {
 580                         log_debugx("capping MaxBurstLength from %zd to %d",
 581                             tmp, conn->conn_max_burst_limit);
 582                         tmp = conn->conn_max_burst_limit;
 583                 }
 584                 conn->conn_max_burst_length = tmp;
 585                 keys_add_int(response_keys, name, tmp);
 586         } else if (strcmp(name, "FirstBurstLength") == 0) {
 587                 tmp = strtoul(value, NULL, 10);
 588                 if (tmp <= 0) {
 589                         login_send_error(request, 0x02, 0x00);
 590                         log_errx(1, "received invalid FirstBurstLength");
 591                 }
 592                 if ((int)tmp > conn->conn_first_burst_limit) {
 593                         log_debugx("capping FirstBurstLength from %zd to %d",
 594                             tmp, conn->conn_first_burst_limit);
 595                         tmp = conn->conn_first_burst_limit;
 596                 }
 597                 conn->conn_first_burst_length = tmp;
 598                 keys_add_int(response_keys, name, tmp);
 599         } else if (strcmp(name, "DefaultTime2Wait") == 0) {
 600                 keys_add(response_keys, name, value);
 601         } else if (strcmp(name, "DefaultTime2Retain") == 0) {
 602                 keys_add(response_keys, name, "0");
 603         } else if (strcmp(name, "MaxOutstandingR2T") == 0) {
 604                 keys_add(response_keys, name, "1");
 605         } else if (strcmp(name, "DataPDUInOrder") == 0) {
 606                 keys_add(response_keys, name, "Yes");
 607         } else if (strcmp(name, "DataSequenceInOrder") == 0) {
 608                 keys_add(response_keys, name, "Yes");
 609         } else if (strcmp(name, "ErrorRecoveryLevel") == 0) {
 610                 keys_add(response_keys, name, "0");
 611         } else if (strcmp(name, "OFMarker") == 0) {
 612                 keys_add(response_keys, name, "No");
 613         } else if (strcmp(name, "IFMarker") == 0) {
 614                 keys_add(response_keys, name, "No");
 615         } else if (strcmp(name, "iSCSIProtocolLevel") == 0) {
 616                 tmp = strtoul(value, NULL, 10);
 617                 if (tmp > 2)
 618                         tmp = 2;
 619                 keys_add_int(response_keys, name, tmp);
 620         } else {
 621                 log_debugx("unknown key \"%s\"; responding "
 622                     "with NotUnderstood", name);
 623                 keys_add(response_keys, name, "NotUnderstood");
 624         }
 625 }
 626
 627 static void
 628 login_redirect(struct pdu *request, const char *target_address)
 629 {
 630         struct pdu *response;
 631         struct iscsi_bhs_login_response *bhslr2;
 632         struct keys *response_keys;
 633
 634         response = login_new_response(request);
 635         login_set_csg(response, login_csg(request));
 636         bhslr2 = (struct iscsi_bhs_login_response *)response->pdu_bhs;
 637         bhslr2->bhslr_status_class = 0x01;
 638         bhslr2->bhslr_status_detail = 0x01;
 639
 640         response_keys = keys_new();
 641         keys_add(response_keys, "TargetAddress", target_address);
 642
 643         keys_save(response_keys, response);
 644         pdu_send(response);
 645         pdu_delete(response);
 646         keys_delete(response_keys);
 647 }
 648
 649 static bool
 650 login_portal_redirect(struct connection *conn, struct pdu *request)
 651 {
 652         const struct portal_group *pg;
 653
 654         pg = conn->conn_portal->p_portal_group;
 655         if (pg->pg_redirection == NULL)
 656                 return (false);
 657
 658         log_debugx("portal-group \"%s\" configured to redirect to %s",
 659             pg->pg_name, pg->pg_redirection);
 660         login_redirect(request, pg->pg_redirection);
 661
 662         return (true);
 663 }
 664
 665 static bool
 666 login_target_redirect(struct connection *conn, struct pdu *request)
 667 {
 668         const char *target_address;
 669
 670         assert(conn->conn_portal->p_portal_group->pg_redirection == NULL);
 671
 672         if (conn->conn_target == NULL)
 673                 return (false);
 674
 675         target_address = conn->conn_target->t_redirection;
 676         if (target_address == NULL)
 677                 return (false);
 678
 679         log_debugx("target \"%s\" configured to redirect to %s",
 680           conn->conn_target->t_name, target_address);
 681         login_redirect(request, target_address);
 682
 683         return (true);
 684 }
 685
 686 static void
 687 login_negotiate(struct connection *conn, struct pdu *request)
 688 {
 689         struct pdu *response;
 690         struct iscsi_bhs_login_response *bhslr2;
 691         struct keys *request_keys, *response_keys;
 692         int i;
 693         bool redirected, skipped_security;
 694
 695         if (conn->conn_session_type == CONN_SESSION_TYPE_NORMAL) {
 696                 /*
 697                  * Query the kernel for various size limits.  In case of
 698                  * offload, it depends on hardware capabilities.
 699                  */
 700                 assert(conn->conn_target != NULL);
 701                 conn->conn_max_recv_data_segment_limit = (1 << 24) - 1;
 702                 conn->conn_max_send_data_segment_limit = (1 << 24) - 1;
 703                 conn->conn_max_burst_limit = (1 << 24) - 1;
 704                 conn->conn_first_burst_limit = (1 << 24) - 1;
 705                 kernel_limits(conn->conn_portal->p_portal_group->pg_offload,
 706                     &conn->conn_max_recv_data_segment_limit,
 707                     &conn->conn_max_send_data_segment_limit,
 708                     &conn->conn_max_burst_limit,
 709                     &conn->conn_first_burst_limit);
 710
 711                 /* We expect legal, usable values at this point. */
 712                 assert(conn->conn_max_recv_data_segment_limit >= 512);
 713                 assert(conn->conn_max_recv_data_segment_limit < (1 << 24));
 714                 assert(conn->conn_max_send_data_segment_limit >= 512);
 715                 assert(conn->conn_max_send_data_segment_limit < (1 << 24));
 716                 assert(conn->conn_max_burst_limit >= 512);
 717                 assert(conn->conn_max_burst_limit < (1 << 24));
 718                 assert(conn->conn_first_burst_limit >= 512);
 719                 assert(conn->conn_first_burst_limit < (1 << 24));
 720                 assert(conn->conn_first_burst_limit <=
 721                     conn->conn_max_burst_limit);
 722
 723                 /*
 724                  * Limit default send length in case it won't be negotiated.
 725                  * We can't do it for other limits, since they may affect both
 726                  * sender and receiver operation, and we must obey defaults.
 727                  */
 728                 if (conn->conn_max_send_data_segment_limit <
 729                     conn->conn_max_send_data_segment_length) {
 730                         conn->conn_max_send_data_segment_length =
 731                             conn->conn_max_send_data_segment_limit;
 732                 }
 733         } else {
 734                 conn->conn_max_recv_data_segment_limit =
 735                     MAX_DATA_SEGMENT_LENGTH;
 736                 conn->conn_max_send_data_segment_limit =
 737                     MAX_DATA_SEGMENT_LENGTH;
 738         }
 739
 740         if (request == NULL) {
 741                 log_debugx("beginning operational parameter negotiation; "
 742                     "waiting for Login PDU");
 743                 request = login_receive(conn, false);
 744                 skipped_security = false;
 745         } else
 746                 skipped_security = true;
 747
 748         /*
 749          * RFC 3720, 10.13.5.  Status-Class and Status-Detail, says
 750          * the redirection SHOULD be accepted by the initiator before
 751          * authentication, but MUST be accepted afterwards; that's
 752          * why we're doing it here and not earlier.
 753          */
 754         redirected = login_target_redirect(conn, request);
 755         if (redirected) {
 756                 log_debugx("initiator redirected; exiting");
 757                 exit(0);
 758         }
 759
 760         request_keys = keys_new();
 761         keys_load(request_keys, request);
 762
 763         response = login_new_response(request);
 764         bhslr2 = (struct iscsi_bhs_login_response *)response->pdu_bhs;
 765         bhslr2->bhslr_tsih = htons(0xbadd);
 766         login_set_csg(response, BHSLR_STAGE_OPERATIONAL_NEGOTIATION);
 767         login_set_nsg(response, BHSLR_STAGE_FULL_FEATURE_PHASE);
 768         response_keys = keys_new();
 769
 770         if (skipped_security &&
 771             conn->conn_session_type == CONN_SESSION_TYPE_NORMAL) {
 772                 if (conn->conn_target->t_alias != NULL)
 773                         keys_add(response_keys,
 774                             "TargetAlias", conn->conn_target->t_alias);
 775                 keys_add_int(response_keys, "TargetPortalGroupTag",
 776                     conn->conn_portal->p_portal_group->pg_tag);
 777         }
 778
 779         for (i = 0; i < KEYS_MAX; i++) {
 780                 if (request_keys->keys_names[i] == NULL)
 781                         break;
 782
 783                 login_negotiate_key(request, request_keys->keys_names[i],
 784                     request_keys->keys_values[i], skipped_security,
 785                     response_keys);
 786         }
 787
 788         /*
 789          * We'd started with usable values at our end.  But a bad initiator
 790          * could have presented a large FirstBurstLength and then a smaller
 791          * MaxBurstLength (in that order) and because we process the key/value
 792          * pairs in the order they are in the request we might have ended up
 793          * with illegal values here.
 794          */
 795         if (conn->conn_session_type == CONN_SESSION_TYPE_NORMAL &&
 796             conn->conn_first_burst_length > conn->conn_max_burst_length) {
 797                 log_errx(1, "initiator sent FirstBurstLength > MaxBurstLength");
 798         }
 799
 800         log_debugx("operational parameter negotiation done; "
 801             "transitioning to Full Feature Phase");
 802
 803         keys_save(response_keys, response);
 804         pdu_send(response);
 805         pdu_delete(response);
 806         keys_delete(response_keys);
 807         pdu_delete(request);
 808         keys_delete(request_keys);
 809 }
 810
 811 static void
 812 login_wait_transition(struct connection *conn)
 813 {
 814         struct pdu *request, *response;
 815         struct iscsi_bhs_login_request *bhslr;
 816
 817         log_debugx("waiting for state transition request");
 818         request = login_receive(conn, false);
 819         bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs;
 820         if ((bhslr->bhslr_flags & BHSLR_FLAGS_TRANSIT) == 0) {
 821                 login_send_error(request, 0x02, 0x00);
 822                 log_errx(1, "got no \"T\" flag after answering AuthMethod");
 823         }
 824
 825         log_debugx("got state transition request");
 826         response = login_new_response(request);
 827         pdu_delete(request);
 828         login_set_nsg(response, BHSLR_STAGE_OPERATIONAL_NEGOTIATION);
 829         pdu_send(response);
 830         pdu_delete(response);
 831
 832         login_negotiate(conn, NULL);
 833 }
 834
 835 void
 836 login(struct connection *conn)
 837 {
 838         struct pdu *request, *response;
 839         struct iscsi_bhs_login_request *bhslr;
 840         struct keys *request_keys, *response_keys;
 841         struct auth_group *ag;
 842         struct portal_group *pg;
 843         const char *initiator_name, *initiator_alias, *session_type,
 844             *target_name, *auth_method;
 845         bool redirected, fail, trans;
 846
 847         /*
 848          * Handle the initial Login Request - figure out required authentication
 849          * method and either transition to the next phase, if no authentication
 850          * is required, or call appropriate authentication code.
 851          */
 852         log_debugx("beginning Login Phase; waiting for Login PDU");
 853         request = login_receive(conn, true);
 854         bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs;
 855         if (bhslr->bhslr_tsih != 0) {
 856                 login_send_error(request, 0x02, 0x0a);
 857                 log_errx(1, "received Login PDU with non-zero TSIH");
 858         }
 859
 860         pg = conn->conn_portal->p_portal_group;
 861
 862         memcpy(conn->conn_initiator_isid, bhslr->bhslr_isid,
 863             sizeof(conn->conn_initiator_isid));
 864
 865         /*
 866          * XXX: Implement the C flag some day.
 867          */
 868         request_keys = keys_new();
 869         keys_load(request_keys, request);
 870
 871         assert(conn->conn_initiator_name == NULL);
 872         initiator_name = keys_find(request_keys, "InitiatorName");
 873         if (initiator_name == NULL) {
 874                 login_send_error(request, 0x02, 0x07);
 875                 log_errx(1, "received Login PDU without InitiatorName");
 876         }
 877         if (valid_iscsi_name(initiator_name) == false) {
 878                 login_send_error(request, 0x02, 0x00);
 879                 log_errx(1, "received Login PDU with invalid InitiatorName");
 880         }
 881         conn->conn_initiator_name = checked_strdup(initiator_name);
 882         log_set_peer_name(conn->conn_initiator_name);
 883         setproctitle("%s (%s)", conn->conn_initiator_addr, conn->conn_initiator_name);
 884
 885         redirected = login_portal_redirect(conn, request);
 886         if (redirected) {
 887                 log_debugx("initiator redirected; exiting");
 888                 exit(0);
 889         }
 890
 891         initiator_alias = keys_find(request_keys, "InitiatorAlias");
 892         if (initiator_alias != NULL)
 893                 conn->conn_initiator_alias = checked_strdup(initiator_alias);
 894
 895         assert(conn->conn_session_type == CONN_SESSION_TYPE_NONE);
 896         session_type = keys_find(request_keys, "SessionType");
 897         if (session_type != NULL) {
 898                 if (strcmp(session_type, "Normal") == 0) {
 899                         conn->conn_session_type = CONN_SESSION_TYPE_NORMAL;
 900                 } else if (strcmp(session_type, "Discovery") == 0) {
 901                         conn->conn_session_type = CONN_SESSION_TYPE_DISCOVERY;
 902                 } else {
 903                         login_send_error(request, 0x02, 0x00);
 904                         log_errx(1, "received Login PDU with invalid "
 905                             "SessionType \"%s\"", session_type);
 906                 }
 907         } else
 908                 conn->conn_session_type = CONN_SESSION_TYPE_NORMAL;
 909
 910         assert(conn->conn_target == NULL);
 911         if (conn->conn_session_type == CONN_SESSION_TYPE_NORMAL) {
 912                 target_name = keys_find(request_keys, "TargetName");
 913                 if (target_name == NULL) {
 914                         login_send_error(request, 0x02, 0x07);
 915                         log_errx(1, "received Login PDU without TargetName");
 916                 }
 917
 918                 conn->conn_port = port_find_in_pg(pg, target_name);
 919                 if (conn->conn_port == NULL) {
 920                         login_send_error(request, 0x02, 0x03);
 921                         log_errx(1, "requested target \"%s\" not found",
 922                             target_name);
 923                 }
 924                 conn->conn_target = conn->conn_port->p_target;
 925         }
 926
 927         /*
 928          * At this point we know what kind of authentication we need.
 929          */
 930         if (conn->conn_session_type == CONN_SESSION_TYPE_NORMAL) {
 931                 ag = conn->conn_port->p_auth_group;
 932                 if (ag == NULL)
 933                         ag = conn->conn_target->t_auth_group;
 934                 if (ag->ag_name != NULL) {
 935                         log_debugx("initiator requests to connect "
 936                             "to target \"%s\"; auth-group \"%s\"",
 937                             conn->conn_target->t_name,
 938                             ag->ag_name);
 939                 } else {
 940                         log_debugx("initiator requests to connect "
 941                             "to target \"%s\"", conn->conn_target->t_name);
 942                 }
 943         } else {
 944                 assert(conn->conn_session_type == CONN_SESSION_TYPE_DISCOVERY);
 945                 ag = pg->pg_discovery_auth_group;
 946                 if (ag->ag_name != NULL) {
 947                         log_debugx("initiator requests "
 948                             "discovery session; auth-group \"%s\"", ag->ag_name);
 949                 } else {
 950                         log_debugx("initiator requests discovery session");
 951                 }
 952         }
 953
 954         if (ag->ag_type == AG_TYPE_DENY) {
 955                 login_send_error(request, 0x02, 0x01);
 956                 log_errx(1, "auth-type is \"deny\"");
 957         }
 958
 959         if (ag->ag_type == AG_TYPE_UNKNOWN) {
 960                 /*
 961                  * This can happen with empty auth-group.
 962                  */
 963                 login_send_error(request, 0x02, 0x01);
 964                 log_errx(1, "auth-type not set, denying access");
 965         }
 966
 967         /*
 968          * Enforce initiator-name and initiator-portal.
 969          */
 970         if (auth_name_check(ag, initiator_name) != 0) {
 971                 login_send_error(request, 0x02, 0x02);
 972                 log_errx(1, "initiator does not match allowed initiator names");
 973         }
 974
 975         if (auth_portal_check(ag, &conn->conn_initiator_sa) != 0) {
 976                 login_send_error(request, 0x02, 0x02);
 977                 log_errx(1, "initiator does not match allowed "
 978                     "initiator portals");
 979         }
 980
 981         /*
 982          * Let's see if the initiator intends to do any kind of authentication
 983          * at all.
 984          */
 985         if (login_csg(request) == BHSLR_STAGE_OPERATIONAL_NEGOTIATION) {
 986                 if (ag->ag_type != AG_TYPE_NO_AUTHENTICATION) {
 987                         login_send_error(request, 0x02, 0x01);
 988                         log_errx(1, "initiator skipped the authentication, "
 989                             "but authentication is required");
 990                 }
 991
 992                 keys_delete(request_keys);
 993
 994                 log_debugx("initiator skipped the authentication, "
 995                     "and we don't need it; proceeding with negotiation");
 996                 login_negotiate(conn, request);
 997                 return;
 998         }
 999
1000         fail = false;
1001         response = login_new_response(request);
1002         response_keys = keys_new();
1003         trans = (bhslr->bhslr_flags & BHSLR_FLAGS_TRANSIT) != 0;
1004         auth_method = keys_find(request_keys, "AuthMethod");
1005         if (ag->ag_type == AG_TYPE_NO_AUTHENTICATION) {
1006                 log_debugx("authentication not required");
1007                 if (auth_method == NULL ||
1008                     login_list_contains(auth_method, "None")) {
1009                         keys_add(response_keys, "AuthMethod", "None");
1010                 } else {
1011                         log_warnx("initiator requests "
1012                             "AuthMethod \"%s\" instead of \"None\"",
1013                             auth_method);
1014                         keys_add(response_keys, "AuthMethod", "Reject");
1015                 }
1016                 if (trans)
1017                         login_set_nsg(response, BHSLR_STAGE_OPERATIONAL_NEGOTIATION);
1018         } else {
1019                 log_debugx("CHAP authentication required");
1020                 if (auth_method == NULL ||
1021                     login_list_contains(auth_method, "CHAP")) {
1022                         keys_add(response_keys, "AuthMethod", "CHAP");
1023                 } else {
1024                         log_warnx("initiator requests unsupported "
1025                             "AuthMethod \"%s\" instead of \"CHAP\"",
1026                             auth_method);
1027                         keys_add(response_keys, "AuthMethod", "Reject");
1028                         fail = true;
1029                 }
1030         }
1031         if (conn->conn_session_type == CONN_SESSION_TYPE_NORMAL) {
1032                 if (conn->conn_target->t_alias != NULL)
1033                         keys_add(response_keys,
1034                             "TargetAlias", conn->conn_target->t_alias);
1035                 keys_add_int(response_keys,
1036                     "TargetPortalGroupTag", pg->pg_tag);
1037         }
1038         keys_save(response_keys, response);
1039
1040         pdu_send(response);
1041         pdu_delete(response);
1042         keys_delete(response_keys);
1043         pdu_delete(request);
1044         keys_delete(request_keys);
1045
1046         if (fail) {
1047                 log_debugx("sent reject for AuthMethod; exiting");
1048                 exit(1);
1049         }
1050
1051         if (ag->ag_type != AG_TYPE_NO_AUTHENTICATION) {
1052                 login_chap(conn, ag);
1053                 login_negotiate(conn, NULL);
1054         } else if (trans) {
1055                 login_negotiate(conn, NULL);
1056         } else {
1057                 login_wait_transition(conn);
1058         }
1059 }