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         bhslr->bhslr_flags |= BHSLR_FLAGS_TRANSIT;
  61 }
  62
  63 static int
  64 login_csg(const struct pdu *request)
  65 {
  66         struct iscsi_bhs_login_request *bhslr;
  67
  68         bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs;
  69
  70         return ((bhslr->bhslr_flags & 0x0C) >> 2);
  71 }
  72
  73 static void
  74 login_set_csg(struct pdu *response, int csg)
  75 {
  76         struct iscsi_bhs_login_response *bhslr;
  77
  78         assert(csg == BHSLR_STAGE_SECURITY_NEGOTIATION ||
  79             csg == BHSLR_STAGE_OPERATIONAL_NEGOTIATION ||
  80             csg == BHSLR_STAGE_FULL_FEATURE_PHASE);
  81
  82         bhslr = (struct iscsi_bhs_login_response *)response->pdu_bhs;
  83
  84         bhslr->bhslr_flags &= 0xF3;
  85         bhslr->bhslr_flags |= csg << 2;
  86 }
  87
  88 static struct pdu *
  89 login_receive(struct connection *conn, bool initial)
  90 {
  91         struct pdu *request;
  92         struct iscsi_bhs_login_request *bhslr;
  93
  94         request = pdu_new(conn);
  95         pdu_receive(request);
  96         if ((request->pdu_bhs->bhs_opcode & ~ISCSI_BHS_OPCODE_IMMEDIATE) !=
  97             ISCSI_BHS_OPCODE_LOGIN_REQUEST) {
  98                 /*
  99                  * The first PDU in session is special - if we receive any PDU
 100                  * different than login request, we have to drop the connection
 101                  * without sending response ("A target receiving any PDU
 102                  * except a Login request before the Login Phase is started MUST
 103                  * immediately terminate the connection on which the PDU
 104                  * was received.")
 105                  */
 106                 if (initial == false)
 107                         login_send_error(request, 0x02, 0x0b);
 108                 log_errx(1, "protocol error: received invalid opcode 0x%x",
 109                     request->pdu_bhs->bhs_opcode);
 110         }
 111         bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs;
 112         /*
 113          * XXX: Implement the C flag some day.
 114          */
 115         if ((bhslr->bhslr_flags & BHSLR_FLAGS_CONTINUE) != 0) {
 116                 login_send_error(request, 0x03, 0x00);
 117                 log_errx(1, "received Login PDU with unsupported \"C\" flag");
 118         }
 119         if (bhslr->bhslr_version_max != 0x00) {
 120                 login_send_error(request, 0x02, 0x05);
 121                 log_errx(1, "received Login PDU with unsupported "
 122                     "Version-max 0x%x", bhslr->bhslr_version_max);
 123         }
 124         if (bhslr->bhslr_version_min != 0x00) {
 125                 login_send_error(request, 0x02, 0x05);
 126                 log_errx(1, "received Login PDU with unsupported "
 127                     "Version-min 0x%x", bhslr->bhslr_version_min);
 128         }
 129         if (ISCSI_SNLT(ntohl(bhslr->bhslr_cmdsn), conn->conn_cmdsn)) {
 130                 login_send_error(request, 0x02, 0x05);
 131                 log_errx(1, "received Login PDU with decreasing CmdSN: "
 132                     "was %u, is %u", conn->conn_cmdsn,
 133                     ntohl(bhslr->bhslr_cmdsn));
 134         }
 135         if (initial == false &&
 136             ntohl(bhslr->bhslr_expstatsn) != conn->conn_statsn) {
 137                 login_send_error(request, 0x02, 0x05);
 138                 log_errx(1, "received Login PDU with wrong ExpStatSN: "
 139                     "is %u, should be %u", ntohl(bhslr->bhslr_expstatsn),
 140                     conn->conn_statsn);
 141         }
 142         conn->conn_cmdsn = ntohl(bhslr->bhslr_cmdsn);
 143
 144         return (request);
 145 }
 146
 147 static struct pdu *
 148 login_new_response(struct pdu *request)
 149 {
 150         struct pdu *response;
 151         struct connection *conn;
 152         struct iscsi_bhs_login_request *bhslr;
 153         struct iscsi_bhs_login_response *bhslr2;
 154
 155         bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs;
 156         conn = request->pdu_connection;
 157
 158         response = pdu_new_response(request);
 159         bhslr2 = (struct iscsi_bhs_login_response *)response->pdu_bhs;
 160         bhslr2->bhslr_opcode = ISCSI_BHS_OPCODE_LOGIN_RESPONSE;
 161         login_set_csg(response, BHSLR_STAGE_SECURITY_NEGOTIATION);
 162         memcpy(bhslr2->bhslr_isid,
 163             bhslr->bhslr_isid, sizeof(bhslr2->bhslr_isid));
 164         bhslr2->bhslr_initiator_task_tag = bhslr->bhslr_initiator_task_tag;
 165         bhslr2->bhslr_statsn = htonl(conn->conn_statsn++);
 166         bhslr2->bhslr_expcmdsn = htonl(conn->conn_cmdsn);
 167         bhslr2->bhslr_maxcmdsn = htonl(conn->conn_cmdsn);
 168
 169         return (response);
 170 }
 171
 172 static void
 173 login_send_error(struct pdu *request, char class, char detail)
 174 {
 175         struct pdu *response;
 176         struct iscsi_bhs_login_response *bhslr2;
 177
 178         log_debugx("sending Login Response PDU with failure class 0x%x/0x%x; "
 179             "see next line for reason", class, detail);
 180         response = login_new_response(request);
 181         bhslr2 = (struct iscsi_bhs_login_response *)response->pdu_bhs;
 182         bhslr2->bhslr_status_class = class;
 183         bhslr2->bhslr_status_detail = detail;
 184
 185         pdu_send(response);
 186         pdu_delete(response);
 187 }
 188
 189 static int
 190 login_list_contains(const char *list, const char *what)
 191 {
 192         char *tofree, *str, *token;
 193
 194         tofree = str = checked_strdup(list);
 195
 196         while ((token = strsep(&str, ",")) != NULL) {
 197                 if (strcmp(token, what) == 0) {
 198                         free(tofree);
 199                         return (1);
 200                 }
 201         }
 202         free(tofree);
 203         return (0);
 204 }
 205
 206 static int
 207 login_list_prefers(const char *list,
 208     const char *choice1, const char *choice2)
 209 {
 210         char *tofree, *str, *token;
 211
 212         tofree = str = checked_strdup(list);
 213
 214         while ((token = strsep(&str, ",")) != NULL) {
 215                 if (strcmp(token, choice1) == 0) {
 216                         free(tofree);
 217                         return (1);
 218                 }
 219                 if (strcmp(token, choice2) == 0) {
 220                         free(tofree);
 221                         return (2);
 222                 }
 223         }
 224         free(tofree);
 225         return (-1);
 226 }
 227
 228 static struct pdu *
 229 login_receive_chap_a(struct connection *conn)
 230 {
 231         struct pdu *request;
 232         struct keys *request_keys;
 233         const char *chap_a;
 234
 235         request = login_receive(conn, false);
 236         request_keys = keys_new();
 237         keys_load(request_keys, request);
 238
 239         chap_a = keys_find(request_keys, "CHAP_A");
 240         if (chap_a == NULL) {
 241                 login_send_error(request, 0x02, 0x07);
 242                 log_errx(1, "received CHAP Login PDU without CHAP_A");
 243         }
 244         if (login_list_contains(chap_a, "5") == 0) {
 245                 login_send_error(request, 0x02, 0x01);
 246                 log_errx(1, "received CHAP Login PDU with unsupported CHAP_A "
 247                     "\"%s\"", chap_a);
 248         }
 249         keys_delete(request_keys);
 250
 251         return (request);
 252 }
 253
 254 static void
 255 login_send_chap_c(struct pdu *request, struct chap *chap)
 256 {
 257         struct pdu *response;
 258         struct keys *response_keys;
 259         char *chap_c, *chap_i;
 260
 261         chap_c = chap_get_challenge(chap);
 262         chap_i = chap_get_id(chap);
 263
 264         response = login_new_response(request);
 265         response_keys = keys_new();
 266         keys_add(response_keys, "CHAP_A", "5");
 267         keys_add(response_keys, "CHAP_I", chap_i);
 268         keys_add(response_keys, "CHAP_C", chap_c);
 269         free(chap_i);
 270         free(chap_c);
 271         keys_save(response_keys, response);
 272         pdu_send(response);
 273         pdu_delete(response);
 274         keys_delete(response_keys);
 275 }
 276
 277 static struct pdu *
 278 login_receive_chap_r(struct connection *conn, struct auth_group *ag,
 279     struct chap *chap, const struct auth **authp)
 280 {
 281         struct pdu *request;
 282         struct keys *request_keys;
 283         const char *chap_n, *chap_r;
 284         const struct auth *auth;
 285         int error;
 286
 287         request = login_receive(conn, false);
 288         request_keys = keys_new();
 289         keys_load(request_keys, request);
 290
 291         chap_n = keys_find(request_keys, "CHAP_N");
 292         if (chap_n == NULL) {
 293                 login_send_error(request, 0x02, 0x07);
 294                 log_errx(1, "received CHAP Login PDU without CHAP_N");
 295         }
 296         chap_r = keys_find(request_keys, "CHAP_R");
 297         if (chap_r == NULL) {
 298                 login_send_error(request, 0x02, 0x07);
 299                 log_errx(1, "received CHAP Login PDU without CHAP_R");
 300         }
 301         error = chap_receive(chap, chap_r);
 302         if (error != 0) {
 303                 login_send_error(request, 0x02, 0x07);
 304                 log_errx(1, "received CHAP Login PDU with malformed CHAP_R");
 305         }
 306
 307         /*
 308          * Verify the response.
 309          */
 310         assert(ag->ag_type == AG_TYPE_CHAP ||
 311             ag->ag_type == AG_TYPE_CHAP_MUTUAL);
 312         auth = auth_find(ag, chap_n);
 313         if (auth == NULL) {
 314                 login_send_error(request, 0x02, 0x01);
 315                 log_errx(1, "received CHAP Login with invalid user \"%s\"",
 316                     chap_n);
 317         }
 318
 319         assert(auth->a_secret != NULL);
 320         assert(strlen(auth->a_secret) > 0);
 321
 322         error = chap_authenticate(chap, auth->a_secret);
 323         if (error != 0) {
 324                 login_send_error(request, 0x02, 0x01);
 325                 log_errx(1, "CHAP authentication failed for user \"%s\"",
 326                     auth->a_user);
 327         }
 328
 329         keys_delete(request_keys);
 330
 331         *authp = auth;
 332         return (request);
 333 }
 334
 335 static void
 336 login_send_chap_success(struct pdu *request,
 337     const struct auth *auth)
 338 {
 339         struct pdu *response;
 340         struct keys *request_keys, *response_keys;
 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         login_set_nsg(response, BHSLR_STAGE_OPERATIONAL_NEGOTIATION);
 348
 349         /*
 350          * Actually, one more thing: mutual authentication.
 351          */
 352         request_keys = keys_new();
 353         keys_load(request_keys, request);
 354         chap_i = keys_find(request_keys, "CHAP_I");
 355         chap_c = keys_find(request_keys, "CHAP_C");
 356         if (chap_i != NULL || chap_c != NULL) {
 357                 if (chap_i == NULL) {
 358                         login_send_error(request, 0x02, 0x07);
 359                         log_errx(1, "initiator requested target "
 360                             "authentication, but didn't send CHAP_I");
 361                 }
 362                 if (chap_c == NULL) {
 363                         login_send_error(request, 0x02, 0x07);
 364                         log_errx(1, "initiator requested target "
 365                             "authentication, but didn't send CHAP_C");
 366                 }
 367                 if (auth->a_auth_group->ag_type != AG_TYPE_CHAP_MUTUAL) {
 368                         login_send_error(request, 0x02, 0x01);
 369                         log_errx(1, "initiator requests target authentication "
 370                             "for user \"%s\", but mutual user/secret "
 371                             "is not set", auth->a_user);
 372                 }
 373
 374                 log_debugx("performing mutual authentication as user \"%s\"",
 375                     auth->a_mutual_user);
 376
 377                 rchap = rchap_new(auth->a_mutual_secret);
 378                 error = rchap_receive(rchap, chap_i, chap_c);
 379                 if (error != 0) {
 380                         login_send_error(request, 0x02, 0x07);
 381                         log_errx(1, "received CHAP Login PDU with malformed "
 382                             "CHAP_I or CHAP_C");
 383                 }
 384                 chap_r = rchap_get_response(rchap);
 385                 rchap_delete(rchap);
 386                 response_keys = keys_new();
 387                 keys_add(response_keys, "CHAP_N", auth->a_mutual_user);
 388                 keys_add(response_keys, "CHAP_R", chap_r);
 389                 free(chap_r);
 390                 keys_save(response_keys, response);
 391                 keys_delete(response_keys);
 392         } else {
 393                 log_debugx("initiator did not request target authentication");
 394         }
 395
 396         keys_delete(request_keys);
 397         pdu_send(response);
 398         pdu_delete(response);
 399 }
 400
 401 static void
 402 login_chap(struct connection *conn, struct auth_group *ag)
 403 {
 404         const struct auth *auth;
 405         struct chap *chap;
 406         struct pdu *request;
 407
 408         /*
 409          * Receive CHAP_A PDU.
 410          */
 411         log_debugx("beginning CHAP authentication; waiting for CHAP_A");
 412         request = login_receive_chap_a(conn);
 413
 414         /*
 415          * Generate the challenge.
 416          */
 417         chap = chap_new();
 418
 419         /*
 420          * Send the challenge.
 421          */
 422         log_debugx("sending CHAP_C, binary challenge size is %zd bytes",
 423             sizeof(chap->chap_challenge));
 424         login_send_chap_c(request, chap);
 425         pdu_delete(request);
 426
 427         /*
 428          * Receive CHAP_N/CHAP_R PDU and authenticate.
 429          */
 430         log_debugx("waiting for CHAP_N/CHAP_R");
 431         request = login_receive_chap_r(conn, ag, chap, &auth);
 432
 433         /*
 434          * Yay, authentication succeeded!
 435          */
 436         log_debugx("authentication succeeded for user \"%s\"; "
 437             "transitioning to Negotiation Phase", auth->a_user);
 438         login_send_chap_success(request, auth);
 439         pdu_delete(request);
 440
 441         /*
 442          * Leave username and CHAP information for discovery().
 443          */
 444         conn->conn_user = auth->a_user;
 445         conn->conn_chap = chap;
 446 }
 447
 448 static void
 449 login_negotiate_key(struct pdu *request, const char *name,
 450     const char *value, bool skipped_security, struct keys *response_keys)
 451 {
 452         int which;
 453         size_t tmp;
 454         struct connection *conn;
 455
 456         conn = request->pdu_connection;
 457
 458         if (strcmp(name, "InitiatorName") == 0) {
 459                 if (!skipped_security)
 460                         log_errx(1, "initiator resent InitiatorName");
 461         } else if (strcmp(name, "SessionType") == 0) {
 462                 if (!skipped_security)
 463                         log_errx(1, "initiator resent SessionType");
 464         } else if (strcmp(name, "TargetName") == 0) {
 465                 if (!skipped_security)
 466                         log_errx(1, "initiator resent TargetName");
 467         } else if (strcmp(name, "InitiatorAlias") == 0) {
 468                 if (conn->conn_initiator_alias != NULL)
 469                         free(conn->conn_initiator_alias);
 470                 conn->conn_initiator_alias = checked_strdup(value);
 471         } else if (strcmp(value, "Irrelevant") == 0) {
 472                 /* Ignore. */
 473         } else if (strcmp(name, "HeaderDigest") == 0) {
 474                 /*
 475                  * We don't handle digests for discovery sessions.
 476                  */
 477                 if (conn->conn_session_type == CONN_SESSION_TYPE_DISCOVERY) {
 478                         log_debugx("discovery session; digests disabled");
 479                         keys_add(response_keys, name, "None");
 480                         return;
 481                 }
 482
 483                 which = login_list_prefers(value, "CRC32C", "None");
 484                 switch (which) {
 485                 case 1:
 486                         log_debugx("initiator prefers CRC32C "
 487                             "for header digest; we'll use it");
 488                         conn->conn_header_digest = CONN_DIGEST_CRC32C;
 489                         keys_add(response_keys, name, "CRC32C");
 490                         break;
 491                 case 2:
 492                         log_debugx("initiator prefers not to do "
 493                             "header digest; we'll comply");
 494                         keys_add(response_keys, name, "None");
 495                         break;
 496                 default:
 497                         log_warnx("initiator sent unrecognized "
 498                             "HeaderDigest value \"%s\"; will use None", value);
 499                         keys_add(response_keys, name, "None");
 500                         break;
 501                 }
 502         } else if (strcmp(name, "DataDigest") == 0) {
 503                 if (conn->conn_session_type == CONN_SESSION_TYPE_DISCOVERY) {
 504                         log_debugx("discovery session; digests disabled");
 505                         keys_add(response_keys, name, "None");
 506                         return;
 507                 }
 508
 509                 which = login_list_prefers(value, "CRC32C", "None");
 510                 switch (which) {
 511                 case 1:
 512                         log_debugx("initiator prefers CRC32C "
 513                             "for data digest; we'll use it");
 514                         conn->conn_data_digest = CONN_DIGEST_CRC32C;
 515                         keys_add(response_keys, name, "CRC32C");
 516                         break;
 517                 case 2:
 518                         log_debugx("initiator prefers not to do "
 519                             "data digest; we'll comply");
 520                         keys_add(response_keys, name, "None");
 521                         break;
 522                 default:
 523                         log_warnx("initiator sent unrecognized "
 524                             "DataDigest value \"%s\"; will use None", value);
 525                         keys_add(response_keys, name, "None");
 526                         break;
 527                 }
 528         } else if (strcmp(name, "MaxConnections") == 0) {
 529                 keys_add(response_keys, name, "1");
 530         } else if (strcmp(name, "InitialR2T") == 0) {
 531                 keys_add(response_keys, name, "Yes");
 532         } else if (strcmp(name, "ImmediateData") == 0) {
 533                 if (conn->conn_session_type == CONN_SESSION_TYPE_DISCOVERY) {
 534                         log_debugx("discovery session; ImmediateData irrelevant");
 535                         keys_add(response_keys, name, "Irrelevant");
 536                 } else {
 537                         if (strcmp(value, "Yes") == 0) {
 538                                 conn->conn_immediate_data = true;
 539                                 keys_add(response_keys, name, "Yes");
 540                         } else {
 541                                 conn->conn_immediate_data = false;
 542                                 keys_add(response_keys, name, "No");
 543                         }
 544                 }
 545         } else if (strcmp(name, "MaxRecvDataSegmentLength") == 0) {
 546                 tmp = strtoul(value, NULL, 10);
 547                 if (tmp <= 0) {
 548                         login_send_error(request, 0x02, 0x00);
 549                         log_errx(1, "received invalid "
 550                             "MaxRecvDataSegmentLength");
 551                 }
 552                 if (tmp > conn->conn_data_segment_limit) {
 553                         log_debugx("capping MaxRecvDataSegmentLength "
 554                             "from %zd to %zd", tmp, conn->conn_data_segment_limit);
 555                         tmp = conn->conn_data_segment_limit;
 556                 }
 557                 conn->conn_max_data_segment_length = tmp;
 558                 keys_add_int(response_keys, name, conn->conn_data_segment_limit);
 559         } else if (strcmp(name, "MaxBurstLength") == 0) {
 560                 tmp = strtoul(value, NULL, 10);
 561                 if (tmp <= 0) {
 562                         login_send_error(request, 0x02, 0x00);
 563                         log_errx(1, "received invalid MaxBurstLength");
 564                 }
 565                 if (tmp > MAX_BURST_LENGTH) {
 566                         log_debugx("capping MaxBurstLength from %zd to %d",
 567                             tmp, MAX_BURST_LENGTH);
 568                         tmp = MAX_BURST_LENGTH;
 569                 }
 570                 conn->conn_max_burst_length = tmp;
 571                 keys_add(response_keys, name, value);
 572         } else if (strcmp(name, "FirstBurstLength") == 0) {
 573                 tmp = strtoul(value, NULL, 10);
 574                 if (tmp <= 0) {
 575                         login_send_error(request, 0x02, 0x00);
 576                         log_errx(1, "received invalid "
 577                             "FirstBurstLength");
 578                 }
 579                 if (tmp > conn->conn_data_segment_limit) {
 580                         log_debugx("capping FirstBurstLength from %zd to %zd",
 581                             tmp, conn->conn_data_segment_limit);
 582                         tmp = conn->conn_data_segment_limit;
 583                 }
 584                 /*
 585                  * We don't pass the value to the kernel; it only enforces
 586                  * hardcoded limit anyway.
 587                  */
 588                 keys_add_int(response_keys, name, tmp);
 589         } else if (strcmp(name, "DefaultTime2Wait") == 0) {
 590                 keys_add(response_keys, name, value);
 591         } else if (strcmp(name, "DefaultTime2Retain") == 0) {
 592                 keys_add(response_keys, name, "0");
 593         } else if (strcmp(name, "MaxOutstandingR2T") == 0) {
 594                 keys_add(response_keys, name, "1");
 595         } else if (strcmp(name, "DataPDUInOrder") == 0) {
 596                 keys_add(response_keys, name, "Yes");
 597         } else if (strcmp(name, "DataSequenceInOrder") == 0) {
 598                 keys_add(response_keys, name, "Yes");
 599         } else if (strcmp(name, "ErrorRecoveryLevel") == 0) {
 600                 keys_add(response_keys, name, "0");
 601         } else if (strcmp(name, "OFMarker") == 0) {
 602                 keys_add(response_keys, name, "No");
 603         } else if (strcmp(name, "IFMarker") == 0) {
 604                 keys_add(response_keys, name, "No");
 605         } else if (strcmp(name, "iSCSIProtocolLevel") == 0) {
 606                 tmp = strtoul(value, NULL, 10);
 607                 if (tmp > 2)
 608                         tmp = 2;
 609                 keys_add_int(response_keys, name, tmp);
 610         } else {
 611                 log_debugx("unknown key \"%s\"; responding "
 612                     "with NotUnderstood", name);
 613                 keys_add(response_keys, name, "NotUnderstood");
 614         }
 615 }
 616
 617 static void
 618 login_redirect(struct pdu *request, const char *target_address)
 619 {
 620         struct pdu *response;
 621         struct iscsi_bhs_login_response *bhslr2;
 622         struct keys *response_keys;
 623
 624         response = login_new_response(request);
 625         login_set_csg(response, login_csg(request));
 626         bhslr2 = (struct iscsi_bhs_login_response *)response->pdu_bhs;
 627         bhslr2->bhslr_status_class = 0x01;
 628         bhslr2->bhslr_status_detail = 0x01;
 629
 630         response_keys = keys_new();
 631         keys_add(response_keys, "TargetAddress", target_address);
 632
 633         keys_save(response_keys, response);
 634         pdu_send(response);
 635         pdu_delete(response);
 636         keys_delete(response_keys);
 637 }
 638
 639 static bool
 640 login_portal_redirect(struct connection *conn, struct pdu *request)
 641 {
 642         const struct portal_group *pg;
 643
 644         pg = conn->conn_portal->p_portal_group;
 645         if (pg->pg_redirection == NULL)
 646                 return (false);
 647
 648         log_debugx("portal-group \"%s\" configured to redirect to %s",
 649             pg->pg_name, pg->pg_redirection);
 650         login_redirect(request, pg->pg_redirection);
 651
 652         return (true);
 653 }
 654
 655 static bool
 656 login_target_redirect(struct connection *conn, struct pdu *request)
 657 {
 658         const char *target_address;
 659
 660         assert(conn->conn_portal->p_portal_group->pg_redirection == NULL);
 661
 662         if (conn->conn_target == NULL)
 663                 return (false);
 664
 665         target_address = conn->conn_target->t_redirection;
 666         if (target_address == NULL)
 667                 return (false);
 668
 669         log_debugx("target \"%s\" configured to redirect to %s",
 670           conn->conn_target->t_name, target_address);
 671         login_redirect(request, target_address);
 672
 673         return (true);
 674 }
 675
 676 static void
 677 login_negotiate(struct connection *conn, struct pdu *request)
 678 {
 679         struct pdu *response;
 680         struct iscsi_bhs_login_response *bhslr2;
 681         struct keys *request_keys, *response_keys;
 682         int i;
 683         bool redirected, skipped_security;
 684
 685         if (conn->conn_session_type == CONN_SESSION_TYPE_NORMAL) {
 686                 /*
 687                  * Query the kernel for MaxDataSegmentLength it can handle.
 688                  * In case of offload, it depends on hardware capabilities.
 689                  */
 690                 assert(conn->conn_target != NULL);
 691                 kernel_limits(conn->conn_portal->p_portal_group->pg_offload,
 692                     &conn->conn_data_segment_limit);
 693         } else {
 694                 conn->conn_data_segment_limit = MAX_DATA_SEGMENT_LENGTH;
 695         }
 696
 697         if (request == NULL) {
 698                 log_debugx("beginning operational parameter negotiation; "
 699                     "waiting for Login PDU");
 700                 request = login_receive(conn, false);
 701                 skipped_security = false;
 702         } else
 703                 skipped_security = true;
 704
 705         /*
 706          * RFC 3720, 10.13.5.  Status-Class and Status-Detail, says
 707          * the redirection SHOULD be accepted by the initiator before
 708          * authentication, but MUST be be accepted afterwards; that's
 709          * why we're doing it here and not earlier.
 710          */
 711         redirected = login_target_redirect(conn, request);
 712         if (redirected) {
 713                 log_debugx("initiator redirected; exiting");
 714                 exit(0);
 715         }
 716
 717         request_keys = keys_new();
 718         keys_load(request_keys, request);
 719
 720         response = login_new_response(request);
 721         bhslr2 = (struct iscsi_bhs_login_response *)response->pdu_bhs;
 722         bhslr2->bhslr_tsih = htons(0xbadd);
 723         login_set_csg(response, BHSLR_STAGE_OPERATIONAL_NEGOTIATION);
 724         login_set_nsg(response, BHSLR_STAGE_FULL_FEATURE_PHASE);
 725         response_keys = keys_new();
 726
 727         if (skipped_security &&
 728             conn->conn_session_type == CONN_SESSION_TYPE_NORMAL) {
 729                 if (conn->conn_target->t_alias != NULL)
 730                         keys_add(response_keys,
 731                             "TargetAlias", conn->conn_target->t_alias);
 732                 keys_add_int(response_keys, "TargetPortalGroupTag",
 733                     conn->conn_portal->p_portal_group->pg_tag);
 734         }
 735
 736         for (i = 0; i < KEYS_MAX; i++) {
 737                 if (request_keys->keys_names[i] == NULL)
 738                         break;
 739
 740                 login_negotiate_key(request, request_keys->keys_names[i],
 741                     request_keys->keys_values[i], skipped_security,
 742                     response_keys);
 743         }
 744
 745         log_debugx("operational parameter negotiation done; "
 746             "transitioning to Full Feature Phase");
 747
 748         keys_save(response_keys, response);
 749         pdu_send(response);
 750         pdu_delete(response);
 751         keys_delete(response_keys);
 752         pdu_delete(request);
 753         keys_delete(request_keys);
 754 }
 755
 756 static void
 757 login_wait_transition(struct connection *conn)
 758 {
 759         struct pdu *request, *response;
 760         struct iscsi_bhs_login_request *bhslr;
 761
 762         log_debugx("waiting for state transition request");
 763         request = login_receive(conn, false);
 764         bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs;
 765         if ((bhslr->bhslr_flags & BHSLR_FLAGS_TRANSIT) == 0) {
 766                 login_send_error(request, 0x02, 0x00);
 767                 log_errx(1, "got no \"T\" flag after answering AuthMethod");
 768         }
 769         pdu_delete(request);
 770
 771         log_debugx("got state transition request");
 772         response = login_new_response(request);
 773         login_set_nsg(response, BHSLR_STAGE_OPERATIONAL_NEGOTIATION);
 774         pdu_send(response);
 775         pdu_delete(response);
 776
 777         login_negotiate(conn, NULL);
 778 }
 779
 780 void
 781 login(struct connection *conn)
 782 {
 783         struct pdu *request, *response;
 784         struct iscsi_bhs_login_request *bhslr;
 785         struct keys *request_keys, *response_keys;
 786         struct auth_group *ag;
 787         struct portal_group *pg;
 788         const char *initiator_name, *initiator_alias, *session_type,
 789             *target_name, *auth_method;
 790         bool redirected, fail, trans;
 791
 792         /*
 793          * Handle the initial Login Request - figure out required authentication
 794          * method and either transition to the next phase, if no authentication
 795          * is required, or call appropriate authentication code.
 796          */
 797         log_debugx("beginning Login Phase; waiting for Login PDU");
 798         request = login_receive(conn, true);
 799         bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs;
 800         if (bhslr->bhslr_tsih != 0) {
 801                 login_send_error(request, 0x02, 0x0a);
 802                 log_errx(1, "received Login PDU with non-zero TSIH");
 803         }
 804
 805         pg = conn->conn_portal->p_portal_group;
 806
 807         memcpy(conn->conn_initiator_isid, bhslr->bhslr_isid,
 808             sizeof(conn->conn_initiator_isid));
 809
 810         /*
 811          * XXX: Implement the C flag some day.
 812          */
 813         request_keys = keys_new();
 814         keys_load(request_keys, request);
 815
 816         assert(conn->conn_initiator_name == NULL);
 817         initiator_name = keys_find(request_keys, "InitiatorName");
 818         if (initiator_name == NULL) {
 819                 login_send_error(request, 0x02, 0x07);
 820                 log_errx(1, "received Login PDU without InitiatorName");
 821         }
 822         if (valid_iscsi_name(initiator_name) == false) {
 823                 login_send_error(request, 0x02, 0x00);
 824                 log_errx(1, "received Login PDU with invalid InitiatorName");
 825         }
 826         conn->conn_initiator_name = checked_strdup(initiator_name);
 827         log_set_peer_name(conn->conn_initiator_name);
 828         setproctitle("%s (%s)", conn->conn_initiator_addr, conn->conn_initiator_name);
 829
 830         redirected = login_portal_redirect(conn, request);
 831         if (redirected) {
 832                 log_debugx("initiator redirected; exiting");
 833                 exit(0);
 834         }
 835
 836         initiator_alias = keys_find(request_keys, "InitiatorAlias");
 837         if (initiator_alias != NULL)
 838                 conn->conn_initiator_alias = checked_strdup(initiator_alias);
 839
 840         assert(conn->conn_session_type == CONN_SESSION_TYPE_NONE);
 841         session_type = keys_find(request_keys, "SessionType");
 842         if (session_type != NULL) {
 843                 if (strcmp(session_type, "Normal") == 0) {
 844                         conn->conn_session_type = CONN_SESSION_TYPE_NORMAL;
 845                 } else if (strcmp(session_type, "Discovery") == 0) {
 846                         conn->conn_session_type = CONN_SESSION_TYPE_DISCOVERY;
 847                 } else {
 848                         login_send_error(request, 0x02, 0x00);
 849                         log_errx(1, "received Login PDU with invalid "
 850                             "SessionType \"%s\"", session_type);
 851                 }
 852         } else
 853                 conn->conn_session_type = CONN_SESSION_TYPE_NORMAL;
 854
 855         assert(conn->conn_target == NULL);
 856         if (conn->conn_session_type == CONN_SESSION_TYPE_NORMAL) {
 857                 target_name = keys_find(request_keys, "TargetName");
 858                 if (target_name == NULL) {
 859                         login_send_error(request, 0x02, 0x07);
 860                         log_errx(1, "received Login PDU without TargetName");
 861                 }
 862
 863                 conn->conn_port = port_find_in_pg(pg, target_name);
 864                 if (conn->conn_port == NULL) {
 865                         login_send_error(request, 0x02, 0x03);
 866                         log_errx(1, "requested target \"%s\" not found",
 867                             target_name);
 868                 }
 869                 conn->conn_target = conn->conn_port->p_target;
 870         }
 871
 872         /*
 873          * At this point we know what kind of authentication we need.
 874          */
 875         if (conn->conn_session_type == CONN_SESSION_TYPE_NORMAL) {
 876                 ag = conn->conn_port->p_auth_group;
 877                 if (ag == NULL)
 878                         ag = conn->conn_target->t_auth_group;
 879                 if (ag->ag_name != NULL) {
 880                         log_debugx("initiator requests to connect "
 881                             "to target \"%s\"; auth-group \"%s\"",
 882                             conn->conn_target->t_name,
 883                             ag->ag_name);
 884                 } else {
 885                         log_debugx("initiator requests to connect "
 886                             "to target \"%s\"", conn->conn_target->t_name);
 887                 }
 888         } else {
 889                 assert(conn->conn_session_type == CONN_SESSION_TYPE_DISCOVERY);
 890                 ag = pg->pg_discovery_auth_group;
 891                 if (ag->ag_name != NULL) {
 892                         log_debugx("initiator requests "
 893                             "discovery session; auth-group \"%s\"", ag->ag_name);
 894                 } else {
 895                         log_debugx("initiator requests discovery session");
 896                 }
 897         }
 898
 899         if (ag->ag_type == AG_TYPE_DENY) {
 900                 login_send_error(request, 0x02, 0x01);
 901                 log_errx(1, "auth-type is \"deny\"");
 902         }
 903
 904         if (ag->ag_type == AG_TYPE_UNKNOWN) {
 905                 /*
 906                  * This can happen with empty auth-group.
 907                  */
 908                 login_send_error(request, 0x02, 0x01);
 909                 log_errx(1, "auth-type not set, denying access");
 910         }
 911
 912         /*
 913          * Enforce initiator-name and initiator-portal.
 914          */
 915         if (auth_name_check(ag, initiator_name) != 0) {
 916                 login_send_error(request, 0x02, 0x02);
 917                 log_errx(1, "initiator does not match allowed initiator names");
 918         }
 919
 920         if (auth_portal_check(ag, &conn->conn_initiator_sa) != 0) {
 921                 login_send_error(request, 0x02, 0x02);
 922                 log_errx(1, "initiator does not match allowed "
 923                     "initiator portals");
 924         }
 925
 926         /*
 927          * Let's see if the initiator intends to do any kind of authentication
 928          * at all.
 929          */
 930         if (login_csg(request) == BHSLR_STAGE_OPERATIONAL_NEGOTIATION) {
 931                 if (ag->ag_type != AG_TYPE_NO_AUTHENTICATION) {
 932                         login_send_error(request, 0x02, 0x01);
 933                         log_errx(1, "initiator skipped the authentication, "
 934                             "but authentication is required");
 935                 }
 936
 937                 keys_delete(request_keys);
 938
 939                 log_debugx("initiator skipped the authentication, "
 940                     "and we don't need it; proceeding with negotiation");
 941                 login_negotiate(conn, request);
 942                 return;
 943         }
 944
 945         fail = false;
 946         response = login_new_response(request);
 947         response_keys = keys_new();
 948         trans = (bhslr->bhslr_flags & BHSLR_FLAGS_TRANSIT) != 0;
 949         auth_method = keys_find(request_keys, "AuthMethod");
 950         if (ag->ag_type == AG_TYPE_NO_AUTHENTICATION) {
 951                 log_debugx("authentication not required");
 952                 if (auth_method == NULL ||
 953                     login_list_contains(auth_method, "None")) {
 954                         keys_add(response_keys, "AuthMethod", "None");
 955                 } else {
 956                         log_warnx("initiator requests "
 957                             "AuthMethod \"%s\" instead of \"None\"",
 958                             auth_method);
 959                         keys_add(response_keys, "AuthMethod", "Reject");
 960                 }
 961                 if (trans)
 962                         login_set_nsg(response, BHSLR_STAGE_OPERATIONAL_NEGOTIATION);
 963         } else {
 964                 log_debugx("CHAP authentication required");
 965                 if (auth_method == NULL ||
 966                     login_list_contains(auth_method, "CHAP")) {
 967                         keys_add(response_keys, "AuthMethod", "CHAP");
 968                 } else {
 969                         log_warnx("initiator requests unsupported "
 970                             "AuthMethod \"%s\" instead of \"CHAP\"",
 971                             auth_method);
 972                         keys_add(response_keys, "AuthMethod", "Reject");
 973                         fail = true;
 974                 }
 975         }
 976         if (conn->conn_session_type == CONN_SESSION_TYPE_NORMAL) {
 977                 if (conn->conn_target->t_alias != NULL)
 978                         keys_add(response_keys,
 979                             "TargetAlias", conn->conn_target->t_alias);
 980                 keys_add_int(response_keys,
 981                     "TargetPortalGroupTag", pg->pg_tag);
 982         }
 983         keys_save(response_keys, response);
 984
 985         pdu_send(response);
 986         pdu_delete(response);
 987         keys_delete(response_keys);
 988         pdu_delete(request);
 989         keys_delete(request_keys);
 990
 991         if (fail) {
 992                 log_debugx("sent reject for AuthMethod; exiting");
 993                 exit(1);
 994         }
 995
 996         if (ag->ag_type != AG_TYPE_NO_AUTHENTICATION) {
 997                 login_chap(conn, ag);
 998                 login_negotiate(conn, NULL);
 999         } else if (trans) {
1000                 login_negotiate(conn, NULL);
1001         } else {
1002                 login_wait_transition(conn);
1003         }
1004 }