usr.sbin/ctld/login.c

   1 /*-
   2  * Copyright (c) 2012 The FreeBSD Foundation
   3  * All rights reserved.
   4  *
   5  * This software was developed by Edward Tomasz Napierala under sponsorship
   6  * from the FreeBSD Foundation.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  */
  30
  31 #include <sys/cdefs.h>
  32 __FBSDID("$FreeBSD$");
  33
  34 #include <assert.h>
  35 #include <stdbool.h>
  36 #include <stdlib.h>
  37 #include <string.h>
  38 #include <unistd.h>
  39 #include <netinet/in.h>
  40
  41 #include "ctld.h"
  42 #include "iscsi_proto.h"
  43
  44 static void login_send_error(struct pdu *request,
  45     char class, char detail);
  46
  47 static void
  48 login_set_nsg(struct pdu *response, int nsg)
  49 {
  50         struct iscsi_bhs_login_response *bhslr;
  51
  52         assert(nsg == BHSLR_STAGE_SECURITY_NEGOTIATION ||
  53             nsg == BHSLR_STAGE_OPERATIONAL_NEGOTIATION ||
  54             nsg == BHSLR_STAGE_FULL_FEATURE_PHASE);
  55
  56         bhslr = (struct iscsi_bhs_login_response *)response->pdu_bhs;
  57
  58         bhslr->bhslr_flags &= 0xFC;
  59         bhslr->bhslr_flags |= nsg;
  60 }
  61
  62 static int
  63 login_csg(const struct pdu *request)
  64 {
  65         struct iscsi_bhs_login_request *bhslr;
  66
  67         bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs;
  68
  69         return ((bhslr->bhslr_flags & 0x0C) >> 2);
  70 }
  71
  72 static void
  73 login_set_csg(struct pdu *response, int csg)
  74 {
  75         struct iscsi_bhs_login_response *bhslr;
  76
  77         assert(csg == BHSLR_STAGE_SECURITY_NEGOTIATION ||
  78             csg == BHSLR_STAGE_OPERATIONAL_NEGOTIATION ||
  79             csg == BHSLR_STAGE_FULL_FEATURE_PHASE);
  80
  81         bhslr = (struct iscsi_bhs_login_response *)response->pdu_bhs;
  82
  83         bhslr->bhslr_flags &= 0xF3;
  84         bhslr->bhslr_flags |= csg << 2;
  85 }
  86
  87 static struct pdu *
  88 login_receive(struct connection *conn, bool initial)
  89 {
  90         struct pdu *request;
  91         struct iscsi_bhs_login_request *bhslr;
  92
  93         request = pdu_new(conn);
  94         pdu_receive(request);
  95         if ((request->pdu_bhs->bhs_opcode & ~ISCSI_BHS_OPCODE_IMMEDIATE) !=
  96             ISCSI_BHS_OPCODE_LOGIN_REQUEST) {
  97                 /*
  98                  * The first PDU in session is special - if we receive any PDU
  99                  * different than login request, we have to drop the connection
 100                  * without sending response ("A target receiving any PDU
 101                  * except a Login request before the Login Phase is started MUST
 102                  * immediately terminate the connection on which the PDU
 103                  * was received.")
 104                  */
 105                 if (initial == false)
 106                         login_send_error(request, 0x02, 0x0b);
 107                 log_errx(1, "protocol error: received invalid opcode 0x%x",
 108                     request->pdu_bhs->bhs_opcode);
 109         }
 110         bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs;
 111         /*
 112          * XXX: Implement the C flag some day.
 113          */
 114         if ((bhslr->bhslr_flags & BHSLR_FLAGS_CONTINUE) != 0) {
 115                 login_send_error(request, 0x03, 0x00);
 116                 log_errx(1, "received Login PDU with unsupported \"C\" flag");
 117         }
 118         if (bhslr->bhslr_version_max != 0x00) {
 119                 login_send_error(request, 0x02, 0x05);
 120                 log_errx(1, "received Login PDU with unsupported "
 121                     "Version-max 0x%x", bhslr->bhslr_version_max);
 122         }
 123         if (bhslr->bhslr_version_min != 0x00) {
 124                 login_send_error(request, 0x02, 0x05);
 125                 log_errx(1, "received Login PDU with unsupported "
 126                     "Version-min 0x%x", bhslr->bhslr_version_min);
 127         }
 128         if (ISCSI_SNLT(ntohl(bhslr->bhslr_cmdsn), conn->conn_cmdsn)) {
 129                 login_send_error(request, 0x02, 0x05);
 130                 log_errx(1, "received Login PDU with decreasing CmdSN: "
 131                     "was %u, is %u", conn->conn_cmdsn,
 132                     ntohl(bhslr->bhslr_cmdsn));
 133         }
 134         if (initial == false &&
 135             ntohl(bhslr->bhslr_expstatsn) != conn->conn_statsn) {
 136                 login_send_error(request, 0x02, 0x05);
 137                 log_errx(1, "received Login PDU with wrong ExpStatSN: "
 138                     "is %u, should be %u", ntohl(bhslr->bhslr_expstatsn),
 139                     conn->conn_statsn);
 140         }
 141         conn->conn_cmdsn = ntohl(bhslr->bhslr_cmdsn);
 142
 143         return (request);
 144 }
 145
 146 static struct pdu *
 147 login_new_response(struct pdu *request)
 148 {
 149         struct pdu *response;
 150         struct connection *conn;
 151         struct iscsi_bhs_login_request *bhslr;
 152         struct iscsi_bhs_login_response *bhslr2;
 153
 154         bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs;
 155         conn = request->pdu_connection;
 156
 157         response = pdu_new_response(request);
 158         bhslr2 = (struct iscsi_bhs_login_response *)response->pdu_bhs;
 159         bhslr2->bhslr_opcode = ISCSI_BHS_OPCODE_LOGIN_RESPONSE;
 160         login_set_csg(response, BHSLR_STAGE_SECURITY_NEGOTIATION);
 161         memcpy(bhslr2->bhslr_isid,
 162             bhslr->bhslr_isid, sizeof(bhslr2->bhslr_isid));
 163         bhslr2->bhslr_initiator_task_tag = bhslr->bhslr_initiator_task_tag;
 164         bhslr2->bhslr_statsn = htonl(conn->conn_statsn++);
 165         bhslr2->bhslr_expcmdsn = htonl(conn->conn_cmdsn);
 166         bhslr2->bhslr_maxcmdsn = htonl(conn->conn_cmdsn);
 167
 168         return (response);
 169 }
 170
 171 static void
 172 login_send_error(struct pdu *request, char class, char detail)
 173 {
 174         struct pdu *response;
 175         struct iscsi_bhs_login_response *bhslr2;
 176
 177         log_debugx("sending Login Response PDU with failure class 0x%x/0x%x; "
 178             "see next line for reason", class, detail);
 179         response = login_new_response(request);
 180         bhslr2 = (struct iscsi_bhs_login_response *)response->pdu_bhs;
 181         bhslr2->bhslr_status_class = class;
 182         bhslr2->bhslr_status_detail = detail;
 183
 184         pdu_send(response);
 185         pdu_delete(response);
 186 }
 187
 188 static int
 189 login_list_contains(const char *list, const char *what)
 190 {
 191         char *tofree, *str, *token;
 192
 193         tofree = str = checked_strdup(list);
 194
 195         while ((token = strsep(&str, ",")) != NULL) {
 196                 if (strcmp(token, what) == 0) {
 197                         free(tofree);
 198                         return (1);
 199                 }
 200         }
 201         free(tofree);
 202         return (0);
 203 }
 204
 205 static int
 206 login_list_prefers(const char *list,
 207     const char *choice1, const char *choice2)
 208 {
 209         char *tofree, *str, *token;
 210
 211         tofree = str = checked_strdup(list);
 212
 213         while ((token = strsep(&str, ",")) != NULL) {
 214                 if (strcmp(token, choice1) == 0) {
 215                         free(tofree);
 216                         return (1);
 217                 }
 218                 if (strcmp(token, choice2) == 0) {
 219                         free(tofree);
 220                         return (2);
 221                 }
 222         }
 223         free(tofree);
 224         return (-1);
 225 }
 226
 227 static struct pdu *
 228 login_receive_chap_a(struct connection *conn)
 229 {
 230         struct pdu *request;
 231         struct keys *request_keys;
 232         const char *chap_a;
 233
 234         request = login_receive(conn, false);
 235         request_keys = keys_new();
 236         keys_load(request_keys, request);
 237
 238         chap_a = keys_find(request_keys, "CHAP_A");
 239         if (chap_a == NULL) {
 240                 login_send_error(request, 0x02, 0x07);
 241                 log_errx(1, "received CHAP Login PDU without CHAP_A");
 242         }
 243         if (login_list_contains(chap_a, "5") == 0) {
 244                 login_send_error(request, 0x02, 0x01);
 245                 log_errx(1, "received CHAP Login PDU with unsupported CHAP_A "
 246                     "\"%s\"", chap_a);
 247         }
 248         keys_delete(request_keys);
 249
 250         return (request);
 251 }
 252
 253 static void
 254 login_send_chap_c(struct pdu *request, struct chap *chap)
 255 {
 256         struct pdu *response;
 257         struct keys *response_keys;
 258         char *chap_c, *chap_i;
 259
 260         chap_c = chap_get_challenge(chap);
 261         chap_i = chap_get_id(chap);
 262
 263         response = login_new_response(request);
 264         response_keys = keys_new();
 265         keys_add(response_keys, "CHAP_A", "5");
 266         keys_add(response_keys, "CHAP_I", chap_i);
 267         keys_add(response_keys, "CHAP_C", chap_c);
 268         free(chap_i);
 269         free(chap_c);
 270         keys_save(response_keys, response);
 271         pdu_send(response);
 272         pdu_delete(response);
 273         keys_delete(response_keys);
 274 }
 275
 276 static struct pdu *
 277 login_receive_chap_r(struct connection *conn, struct auth_group *ag,
 278     struct chap *chap, const struct auth **authp)
 279 {
 280         struct pdu *request;
 281         struct keys *request_keys;
 282         const char *chap_n, *chap_r;
 283         const struct auth *auth;
 284         int error;
 285
 286         request = login_receive(conn, false);
 287         request_keys = keys_new();
 288         keys_load(request_keys, request);
 289
 290         chap_n = keys_find(request_keys, "CHAP_N");
 291         if (chap_n == NULL) {
 292                 login_send_error(request, 0x02, 0x07);
 293                 log_errx(1, "received CHAP Login PDU without CHAP_N");
 294         }
 295         chap_r = keys_find(request_keys, "CHAP_R");
 296         if (chap_r == NULL) {
 297                 login_send_error(request, 0x02, 0x07);
 298                 log_errx(1, "received CHAP Login PDU without CHAP_R");
 299         }
 300         error = chap_receive(chap, chap_r);
 301         if (error != 0) {
 302                 login_send_error(request, 0x02, 0x07);
 303                 log_errx(1, "received CHAP Login PDU with malformed CHAP_R");
 304         }
 305
 306         /*
 307          * Verify the response.
 308          */
 309         assert(ag->ag_type == AG_TYPE_CHAP ||
 310             ag->ag_type == AG_TYPE_CHAP_MUTUAL);
 311         auth = auth_find(ag, chap_n);
 312         if (auth == NULL) {
 313                 login_send_error(request, 0x02, 0x01);
 314                 log_errx(1, "received CHAP Login with invalid user \"%s\"",
 315                     chap_n);
 316         }
 317
 318         assert(auth->a_secret != NULL);
 319         assert(strlen(auth->a_secret) > 0);
 320
 321         error = chap_authenticate(chap, auth->a_secret);
 322         if (error != 0) {
 323                 login_send_error(request, 0x02, 0x01);
 324                 log_errx(1, "CHAP authentication failed for user \"%s\"",
 325                     auth->a_user);
 326         }
 327
 328         keys_delete(request_keys);
 329
 330         *authp = auth;
 331         return (request);
 332 }
 333
 334 static void
 335 login_send_chap_success(struct pdu *request,
 336     const struct auth *auth)
 337 {
 338         struct pdu *response;
 339         struct keys *request_keys, *response_keys;
 340         struct iscsi_bhs_login_response *bhslr2;
 341         struct rchap *rchap;
 342         const char *chap_i, *chap_c;
 343         char *chap_r;
 344         int error;
 345
 346         response = login_new_response(request);
 347         bhslr2 = (struct iscsi_bhs_login_response *)response->pdu_bhs;
 348         bhslr2->bhslr_flags |= BHSLR_FLAGS_TRANSIT;
 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 Negotiation Phase", 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                 if (tmp > conn->conn_data_segment_limit) {
 555                         log_debugx("capping MaxRecvDataSegmentLength "
 556                             "from %zd to %zd", tmp, conn->conn_data_segment_limit);
 557                         tmp = conn->conn_data_segment_limit;
 558                 }
 559                 conn->conn_max_data_segment_length = tmp;
 560                 keys_add_int(response_keys, name, tmp);
 561         } else if (strcmp(name, "MaxBurstLength") == 0) {
 562                 tmp = strtoul(value, NULL, 10);
 563                 if (tmp <= 0) {
 564                         login_send_error(request, 0x02, 0x00);
 565                         log_errx(1, "received invalid MaxBurstLength");
 566                 }
 567                 if (tmp > MAX_BURST_LENGTH) {
 568                         log_debugx("capping MaxBurstLength from %zd to %d",
 569                             tmp, MAX_BURST_LENGTH);
 570                         tmp = MAX_BURST_LENGTH;
 571                 }
 572                 conn->conn_max_burst_length = tmp;
 573                 keys_add(response_keys, name, value);
 574         } else if (strcmp(name, "FirstBurstLength") == 0) {
 575                 tmp = strtoul(value, NULL, 10);
 576                 if (tmp <= 0) {
 577                         login_send_error(request, 0x02, 0x00);
 578                         log_errx(1, "received invalid "
 579                             "FirstBurstLength");
 580                 }
 581                 if (tmp > conn->conn_data_segment_limit) {
 582                         log_debugx("capping FirstBurstLength from %zd to %zd",
 583                             tmp, conn->conn_data_segment_limit);
 584                         tmp = conn->conn_data_segment_limit;
 585                 }
 586                 /*
 587                  * We don't pass the value to the kernel; it only enforces
 588                  * hardcoded limit anyway.
 589                  */
 590                 keys_add_int(response_keys, name, tmp);
 591         } else if (strcmp(name, "DefaultTime2Wait") == 0) {
 592                 keys_add(response_keys, name, value);
 593         } else if (strcmp(name, "DefaultTime2Retain") == 0) {
 594                 keys_add(response_keys, name, "0");
 595         } else if (strcmp(name, "MaxOutstandingR2T") == 0) {
 596                 keys_add(response_keys, name, "1");
 597         } else if (strcmp(name, "DataPDUInOrder") == 0) {
 598                 keys_add(response_keys, name, "Yes");
 599         } else if (strcmp(name, "DataSequenceInOrder") == 0) {
 600                 keys_add(response_keys, name, "Yes");
 601         } else if (strcmp(name, "ErrorRecoveryLevel") == 0) {
 602                 keys_add(response_keys, name, "0");
 603         } else if (strcmp(name, "OFMarker") == 0) {
 604                 keys_add(response_keys, name, "No");
 605         } else if (strcmp(name, "IFMarker") == 0) {
 606                 keys_add(response_keys, name, "No");
 607         } else {
 608                 log_debugx("unknown key \"%s\"; responding "
 609                     "with NotUnderstood", name);
 610                 keys_add(response_keys, name, "NotUnderstood");
 611         }
 612 }
 613
 614 static void
 615 login_redirect(struct pdu *request, const char *target_address)
 616 {
 617         struct pdu *response;
 618         struct iscsi_bhs_login_response *bhslr2;
 619         struct keys *response_keys;
 620
 621         response = login_new_response(request);
 622         login_set_csg(response, login_csg(request));
 623         bhslr2 = (struct iscsi_bhs_login_response *)response->pdu_bhs;
 624         bhslr2->bhslr_status_class = 0x01;
 625         bhslr2->bhslr_status_detail = 0x01;
 626
 627         response_keys = keys_new();
 628         keys_add(response_keys, "TargetAddress", target_address);
 629
 630         keys_save(response_keys, response);
 631         pdu_send(response);
 632         pdu_delete(response);
 633         keys_delete(response_keys);
 634 }
 635
 636 static bool
 637 login_portal_redirect(struct connection *conn, struct pdu *request)
 638 {
 639         const struct portal_group *pg;
 640
 641         pg = conn->conn_portal->p_portal_group;
 642         if (pg->pg_redirection == NULL)
 643                 return (false);
 644
 645         log_debugx("portal-group \"%s\" configured to redirect to %s",
 646             pg->pg_name, pg->pg_redirection);
 647         login_redirect(request, pg->pg_redirection);
 648
 649         return (true);
 650 }
 651
 652 static bool
 653 login_target_redirect(struct connection *conn, struct pdu *request)
 654 {
 655         const char *target_address;
 656
 657         assert(conn->conn_portal->p_portal_group->pg_redirection == NULL);
 658
 659         if (conn->conn_target == NULL)
 660                 return (false);
 661
 662         target_address = conn->conn_target->t_redirection;
 663         if (target_address == NULL)
 664                 return (false);
 665
 666         log_debugx("target \"%s\" configured to redirect to %s",
 667           conn->conn_target->t_name, target_address);
 668         login_redirect(request, target_address);
 669
 670         return (true);
 671 }
 672
 673 static void
 674 login_negotiate(struct connection *conn, struct pdu *request)
 675 {
 676         struct pdu *response;
 677         struct iscsi_bhs_login_response *bhslr2;
 678         struct keys *request_keys, *response_keys;
 679         int i;
 680         bool redirected, skipped_security;
 681
 682         if (conn->conn_session_type == CONN_SESSION_TYPE_NORMAL) {
 683                 /*
 684                  * Query the kernel for MaxDataSegmentLength it can handle.
 685                  * In case of offload, it depends on hardware capabilities.
 686                  */
 687                 assert(conn->conn_target != NULL);
 688                 kernel_limits(conn->conn_portal->p_portal_group->pg_offload,
 689                     &conn->conn_data_segment_limit);
 690         } else {
 691                 conn->conn_data_segment_limit = MAX_DATA_SEGMENT_LENGTH;
 692         }
 693
 694         if (request == NULL) {
 695                 log_debugx("beginning operational parameter negotiation; "
 696                     "waiting for Login PDU");
 697                 request = login_receive(conn, false);
 698                 skipped_security = false;
 699         } else
 700                 skipped_security = true;
 701
 702         /*
 703          * RFC 3720, 10.13.5.  Status-Class and Status-Detail, says
 704          * the redirection SHOULD be accepted by the initiator before
 705          * authentication, but MUST be be accepted afterwards; that's
 706          * why we're doing it here and not earlier.
 707          */
 708         redirected = login_target_redirect(conn, request);
 709         if (redirected) {
 710                 log_debugx("initiator redirected; exiting");
 711                 exit(0);
 712         }
 713
 714         request_keys = keys_new();
 715         keys_load(request_keys, request);
 716
 717         response = login_new_response(request);
 718         bhslr2 = (struct iscsi_bhs_login_response *)response->pdu_bhs;
 719         bhslr2->bhslr_flags |= BHSLR_FLAGS_TRANSIT;
 720         bhslr2->bhslr_tsih = htons(0xbadd);
 721         login_set_csg(response, BHSLR_STAGE_OPERATIONAL_NEGOTIATION);
 722         login_set_nsg(response, BHSLR_STAGE_FULL_FEATURE_PHASE);
 723         response_keys = keys_new();
 724
 725         if (skipped_security &&
 726             conn->conn_session_type == CONN_SESSION_TYPE_NORMAL) {
 727                 if (conn->conn_target->t_alias != NULL)
 728                         keys_add(response_keys,
 729                             "TargetAlias", conn->conn_target->t_alias);
 730                 keys_add_int(response_keys, "TargetPortalGroupTag",
 731                     conn->conn_portal->p_portal_group->pg_tag);
 732         }
 733
 734         for (i = 0; i < KEYS_MAX; i++) {
 735                 if (request_keys->keys_names[i] == NULL)
 736                         break;
 737
 738                 login_negotiate_key(request, request_keys->keys_names[i],
 739                     request_keys->keys_values[i], skipped_security,
 740                     response_keys);
 741         }
 742
 743         log_debugx("operational parameter negotiation done; "
 744             "transitioning to Full Feature Phase");
 745
 746         keys_save(response_keys, response);
 747         pdu_send(response);
 748         pdu_delete(response);
 749         keys_delete(response_keys);
 750         pdu_delete(request);
 751         keys_delete(request_keys);
 752 }
 753
 754 void
 755 login(struct connection *conn)
 756 {
 757         struct pdu *request, *response;
 758         struct iscsi_bhs_login_request *bhslr;
 759         struct iscsi_bhs_login_response *bhslr2;
 760         struct keys *request_keys, *response_keys;
 761         struct auth_group *ag;
 762         struct portal_group *pg;
 763         const char *initiator_name, *initiator_alias, *session_type,
 764             *target_name, *auth_method;
 765         bool redirected;
 766
 767         /*
 768          * Handle the initial Login Request - figure out required authentication
 769          * method and either transition to the next phase, if no authentication
 770          * is required, or call appropriate authentication code.
 771          */
 772         log_debugx("beginning Login Phase; waiting for Login PDU");
 773         request = login_receive(conn, true);
 774         bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs;
 775         if (bhslr->bhslr_tsih != 0) {
 776                 login_send_error(request, 0x02, 0x0a);
 777                 log_errx(1, "received Login PDU with non-zero TSIH");
 778         }
 779
 780         pg = conn->conn_portal->p_portal_group;
 781
 782         memcpy(conn->conn_initiator_isid, bhslr->bhslr_isid,
 783             sizeof(conn->conn_initiator_isid));
 784
 785         /*
 786          * XXX: Implement the C flag some day.
 787          */
 788         request_keys = keys_new();
 789         keys_load(request_keys, request);
 790
 791         assert(conn->conn_initiator_name == NULL);
 792         initiator_name = keys_find(request_keys, "InitiatorName");
 793         if (initiator_name == NULL) {
 794                 login_send_error(request, 0x02, 0x07);
 795                 log_errx(1, "received Login PDU without InitiatorName");
 796         }
 797         if (valid_iscsi_name(initiator_name) == false) {
 798                 login_send_error(request, 0x02, 0x00);
 799                 log_errx(1, "received Login PDU with invalid InitiatorName");
 800         }
 801         conn->conn_initiator_name = checked_strdup(initiator_name);
 802         log_set_peer_name(conn->conn_initiator_name);
 803         setproctitle("%s (%s)", conn->conn_initiator_addr, conn->conn_initiator_name);
 804
 805         redirected = login_portal_redirect(conn, request);
 806         if (redirected) {
 807                 log_debugx("initiator redirected; exiting");
 808                 exit(0);
 809         }
 810
 811         initiator_alias = keys_find(request_keys, "InitiatorAlias");
 812         if (initiator_alias != NULL)
 813                 conn->conn_initiator_alias = checked_strdup(initiator_alias);
 814
 815         assert(conn->conn_session_type == CONN_SESSION_TYPE_NONE);
 816         session_type = keys_find(request_keys, "SessionType");
 817         if (session_type != NULL) {
 818                 if (strcmp(session_type, "Normal") == 0) {
 819                         conn->conn_session_type = CONN_SESSION_TYPE_NORMAL;
 820                 } else if (strcmp(session_type, "Discovery") == 0) {
 821                         conn->conn_session_type = CONN_SESSION_TYPE_DISCOVERY;
 822                 } else {
 823                         login_send_error(request, 0x02, 0x00);
 824                         log_errx(1, "received Login PDU with invalid "
 825                             "SessionType \"%s\"", session_type);
 826                 }
 827         } else
 828                 conn->conn_session_type = CONN_SESSION_TYPE_NORMAL;
 829
 830         assert(conn->conn_target == NULL);
 831         if (conn->conn_session_type == CONN_SESSION_TYPE_NORMAL) {
 832                 target_name = keys_find(request_keys, "TargetName");
 833                 if (target_name == NULL) {
 834                         login_send_error(request, 0x02, 0x07);
 835                         log_errx(1, "received Login PDU without TargetName");
 836                 }
 837
 838                 conn->conn_port = port_find_in_pg(pg, target_name);
 839                 if (conn->conn_port == NULL) {
 840                         login_send_error(request, 0x02, 0x03);
 841                         log_errx(1, "requested target \"%s\" not found",
 842                             target_name);
 843                 }
 844                 conn->conn_target = conn->conn_port->p_target;
 845         }
 846
 847         /*
 848          * At this point we know what kind of authentication we need.
 849          */
 850         if (conn->conn_session_type == CONN_SESSION_TYPE_NORMAL) {
 851                 ag = conn->conn_port->p_auth_group;
 852                 if (ag == NULL)
 853                         ag = conn->conn_target->t_auth_group;
 854                 if (ag->ag_name != NULL) {
 855                         log_debugx("initiator requests to connect "
 856                             "to target \"%s\"; auth-group \"%s\"",
 857                             conn->conn_target->t_name,
 858                             ag->ag_name);
 859                 } else {
 860                         log_debugx("initiator requests to connect "
 861                             "to target \"%s\"", conn->conn_target->t_name);
 862                 }
 863         } else {
 864                 assert(conn->conn_session_type == CONN_SESSION_TYPE_DISCOVERY);
 865                 ag = pg->pg_discovery_auth_group;
 866                 if (ag->ag_name != NULL) {
 867                         log_debugx("initiator requests "
 868                             "discovery session; auth-group \"%s\"", ag->ag_name);
 869                 } else {
 870                         log_debugx("initiator requests discovery session");
 871                 }
 872         }
 873
 874         /*
 875          * Enforce initiator-name and initiator-portal.
 876          */
 877         if (auth_name_check(ag, initiator_name) != 0) {
 878                 login_send_error(request, 0x02, 0x02);
 879                 log_errx(1, "initiator does not match allowed initiator names");
 880         }
 881
 882         if (auth_portal_check(ag, &conn->conn_initiator_sa) != 0) {
 883                 login_send_error(request, 0x02, 0x02);
 884                 log_errx(1, "initiator does not match allowed "
 885                     "initiator portals");
 886         }
 887
 888         /*
 889          * Let's see if the initiator intends to do any kind of authentication
 890          * at all.
 891          */
 892         if (login_csg(request) == BHSLR_STAGE_OPERATIONAL_NEGOTIATION) {
 893                 if (ag->ag_type != AG_TYPE_NO_AUTHENTICATION) {
 894                         login_send_error(request, 0x02, 0x01);
 895                         log_errx(1, "initiator skipped the authentication, "
 896                             "but authentication is required");
 897                 }
 898
 899                 keys_delete(request_keys);
 900
 901                 log_debugx("initiator skipped the authentication, "
 902                     "and we don't need it; proceeding with negotiation");
 903                 login_negotiate(conn, request);
 904                 return;
 905         }
 906
 907         if (ag->ag_type == AG_TYPE_NO_AUTHENTICATION) {
 908                 /*
 909                  * Initiator might want to to authenticate,
 910                  * but we don't need it.
 911                  */
 912                 log_debugx("authentication not required; "
 913                     "transitioning to operational parameter negotiation");
 914
 915                 if ((bhslr->bhslr_flags & BHSLR_FLAGS_TRANSIT) == 0)
 916                         log_warnx("initiator did not set the \"T\" flag; "
 917                             "transitioning anyway");
 918
 919                 response = login_new_response(request);
 920                 bhslr2 = (struct iscsi_bhs_login_response *)response->pdu_bhs;
 921                 bhslr2->bhslr_flags |= BHSLR_FLAGS_TRANSIT;
 922                 login_set_nsg(response, BHSLR_STAGE_OPERATIONAL_NEGOTIATION);
 923                 response_keys = keys_new();
 924                 /*
 925                  * Required by Linux initiator.
 926                  */
 927                 auth_method = keys_find(request_keys, "AuthMethod");
 928                 if (auth_method != NULL &&
 929                     login_list_contains(auth_method, "None"))
 930                         keys_add(response_keys, "AuthMethod", "None");
 931
 932                 if (conn->conn_session_type == CONN_SESSION_TYPE_NORMAL) {
 933                         if (conn->conn_target->t_alias != NULL)
 934                                 keys_add(response_keys,
 935                                     "TargetAlias", conn->conn_target->t_alias);
 936                         keys_add_int(response_keys,
 937                             "TargetPortalGroupTag", pg->pg_tag);
 938                 }
 939                 keys_save(response_keys, response);
 940                 pdu_send(response);
 941                 pdu_delete(response);
 942                 keys_delete(response_keys);
 943                 pdu_delete(request);
 944                 keys_delete(request_keys);
 945
 946                 login_negotiate(conn, NULL);
 947                 return;
 948         }
 949
 950         if (ag->ag_type == AG_TYPE_DENY) {
 951                 login_send_error(request, 0x02, 0x01);
 952                 log_errx(1, "auth-type is \"deny\"");
 953         }
 954
 955         if (ag->ag_type == AG_TYPE_UNKNOWN) {
 956                 /*
 957                  * This can happen with empty auth-group.
 958                  */
 959                 login_send_error(request, 0x02, 0x01);
 960                 log_errx(1, "auth-type not set, denying access");
 961         }
 962
 963         log_debugx("CHAP authentication required");
 964
 965         auth_method = keys_find(request_keys, "AuthMethod");
 966         if (auth_method == NULL) {
 967                 login_send_error(request, 0x02, 0x07);
 968                 log_errx(1, "received Login PDU without AuthMethod");
 969         }
 970         /*
 971          * XXX: This should be Reject, not just a login failure (5.3.2).
 972          */
 973         if (login_list_contains(auth_method, "CHAP") == 0) {
 974                 login_send_error(request, 0x02, 0x01);
 975                 log_errx(1, "initiator requests unsupported AuthMethod \"%s\" "
 976                     "instead of \"CHAP\"", auth_method);
 977         }
 978
 979         response = login_new_response(request);
 980
 981         response_keys = keys_new();
 982         keys_add(response_keys, "AuthMethod", "CHAP");
 983         if (conn->conn_session_type == CONN_SESSION_TYPE_NORMAL) {
 984                 if (conn->conn_target->t_alias != NULL)
 985                         keys_add(response_keys,
 986                             "TargetAlias", conn->conn_target->t_alias);
 987                 keys_add_int(response_keys,
 988                     "TargetPortalGroupTag", pg->pg_tag);
 989         }
 990         keys_save(response_keys, response);
 991
 992         pdu_send(response);
 993         pdu_delete(response);
 994         keys_delete(response_keys);
 995         pdu_delete(request);
 996         keys_delete(request_keys);
 997
 998         login_chap(conn, ag);
 999
1000         login_negotiate(conn, NULL);
1001 }