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 (initial == false &&
 130             ISCSI_SNLT(ntohl(bhslr->bhslr_cmdsn), conn->conn_cmdsn)) {
 131                 login_send_error(request, 0x02, 0x00);
 132                 log_errx(1, "received Login PDU with decreasing CmdSN: "
 133                     "was %u, is %u", conn->conn_cmdsn,
 134                     ntohl(bhslr->bhslr_cmdsn));
 135         }
 136         if (initial == false &&
 137             ntohl(bhslr->bhslr_expstatsn) != conn->conn_statsn) {
 138                 login_send_error(request, 0x02, 0x00);
 139                 log_errx(1, "received Login PDU with wrong ExpStatSN: "
 140                     "is %u, should be %u", ntohl(bhslr->bhslr_expstatsn),
 141                     conn->conn_statsn);
 142         }
 143         conn->conn_cmdsn = ntohl(bhslr->bhslr_cmdsn);
 144
 145         return (request);
 146 }
 147
 148 static struct pdu *
 149 login_new_response(struct pdu *request)
 150 {
 151         struct pdu *response;
 152         struct connection *conn;
 153         struct iscsi_bhs_login_request *bhslr;
 154         struct iscsi_bhs_login_response *bhslr2;
 155
 156         bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs;
 157         conn = request->pdu_connection;
 158
 159         response = pdu_new_response(request);
 160         bhslr2 = (struct iscsi_bhs_login_response *)response->pdu_bhs;
 161         bhslr2->bhslr_opcode = ISCSI_BHS_OPCODE_LOGIN_RESPONSE;
 162         login_set_csg(response, BHSLR_STAGE_SECURITY_NEGOTIATION);
 163         memcpy(bhslr2->bhslr_isid,
 164             bhslr->bhslr_isid, sizeof(bhslr2->bhslr_isid));
 165         bhslr2->bhslr_initiator_task_tag = bhslr->bhslr_initiator_task_tag;
 166         bhslr2->bhslr_statsn = htonl(conn->conn_statsn++);
 167         bhslr2->bhslr_expcmdsn = htonl(conn->conn_cmdsn);
 168         bhslr2->bhslr_maxcmdsn = htonl(conn->conn_cmdsn);
 169
 170         return (response);
 171 }
 172
 173 static void
 174 login_send_error(struct pdu *request, char class, char detail)
 175 {
 176         struct pdu *response;
 177         struct iscsi_bhs_login_response *bhslr2;
 178
 179         log_debugx("sending Login Response PDU with failure class 0x%x/0x%x; "
 180             "see next line for reason", class, detail);
 181         response = login_new_response(request);
 182         bhslr2 = (struct iscsi_bhs_login_response *)response->pdu_bhs;
 183         bhslr2->bhslr_status_class = class;
 184         bhslr2->bhslr_status_detail = detail;
 185
 186         pdu_send(response);
 187         pdu_delete(response);
 188 }
 189
 190 static int
 191 login_list_contains(const char *list, const char *what)
 192 {
 193         char *tofree, *str, *token;
 194
 195         tofree = str = checked_strdup(list);
 196
 197         while ((token = strsep(&str, ",")) != NULL) {
 198                 if (strcmp(token, what) == 0) {
 199                         free(tofree);
 200                         return (1);
 201                 }
 202         }
 203         free(tofree);
 204         return (0);
 205 }
 206
 207 static int
 208 login_list_prefers(const char *list,
 209     const char *choice1, const char *choice2)
 210 {
 211         char *tofree, *str, *token;
 212
 213         tofree = str = checked_strdup(list);
 214
 215         while ((token = strsep(&str, ",")) != NULL) {
 216                 if (strcmp(token, choice1) == 0) {
 217                         free(tofree);
 218                         return (1);
 219                 }
 220                 if (strcmp(token, choice2) == 0) {
 221                         free(tofree);
 222                         return (2);
 223                 }
 224         }
 225         free(tofree);
 226         return (-1);
 227 }
 228
 229 static struct pdu *
 230 login_receive_chap_a(struct connection *conn)
 231 {
 232         struct pdu *request;
 233         struct keys *request_keys;
 234         const char *chap_a;
 235
 236         request = login_receive(conn, false);
 237         request_keys = keys_new();
 238         keys_load(request_keys, request);
 239
 240         chap_a = keys_find(request_keys, "CHAP_A");
 241         if (chap_a == NULL) {
 242                 login_send_error(request, 0x02, 0x07);
 243                 log_errx(1, "received CHAP Login PDU without CHAP_A");
 244         }
 245         if (login_list_contains(chap_a, "5") == 0) {
 246                 login_send_error(request, 0x02, 0x01);
 247                 log_errx(1, "received CHAP Login PDU with unsupported CHAP_A "
 248                     "\"%s\"", chap_a);
 249         }
 250         keys_delete(request_keys);
 251
 252         return (request);
 253 }
 254
 255 static void
 256 login_send_chap_c(struct pdu *request, struct chap *chap)
 257 {
 258         struct pdu *response;
 259         struct keys *response_keys;
 260         char *chap_c, *chap_i;
 261
 262         chap_c = chap_get_challenge(chap);
 263         chap_i = chap_get_id(chap);
 264
 265         response = login_new_response(request);
 266         response_keys = keys_new();
 267         keys_add(response_keys, "CHAP_A", "5");
 268         keys_add(response_keys, "CHAP_I", chap_i);
 269         keys_add(response_keys, "CHAP_C", chap_c);
 270         free(chap_i);
 271         free(chap_c);
 272         keys_save(response_keys, response);
 273         pdu_send(response);
 274         pdu_delete(response);
 275         keys_delete(response_keys);
 276 }
 277
 278 static struct pdu *
 279 login_receive_chap_r(struct connection *conn, struct auth_group *ag,
 280     struct chap *chap, const struct auth **authp)
 281 {
 282         struct pdu *request;
 283         struct keys *request_keys;
 284         const char *chap_n, *chap_r;
 285         const struct auth *auth;
 286         int error;
 287
 288         request = login_receive(conn, false);
 289         request_keys = keys_new();
 290         keys_load(request_keys, request);
 291
 292         chap_n = keys_find(request_keys, "CHAP_N");
 293         if (chap_n == NULL) {
 294                 login_send_error(request, 0x02, 0x07);
 295                 log_errx(1, "received CHAP Login PDU without CHAP_N");
 296         }
 297         chap_r = keys_find(request_keys, "CHAP_R");
 298         if (chap_r == NULL) {
 299                 login_send_error(request, 0x02, 0x07);
 300                 log_errx(1, "received CHAP Login PDU without CHAP_R");
 301         }
 302         error = chap_receive(chap, chap_r);
 303         if (error != 0) {
 304                 login_send_error(request, 0x02, 0x07);
 305                 log_errx(1, "received CHAP Login PDU with malformed CHAP_R");
 306         }
 307
 308         /*
 309          * Verify the response.
 310          */
 311         assert(ag->ag_type == AG_TYPE_CHAP ||
 312             ag->ag_type == AG_TYPE_CHAP_MUTUAL);
 313         auth = auth_find(ag, chap_n);
 314         if (auth == NULL) {
 315                 login_send_error(request, 0x02, 0x01);
 316                 log_errx(1, "received CHAP Login with invalid user \"%s\"",
 317                     chap_n);
 318         }
 319
 320         assert(auth->a_secret != NULL);
 321         assert(strlen(auth->a_secret) > 0);
 322
 323         error = chap_authenticate(chap, auth->a_secret);
 324         if (error != 0) {
 325                 login_send_error(request, 0x02, 0x01);
 326                 log_errx(1, "CHAP authentication failed for user \"%s\"",
 327                     auth->a_user);
 328         }
 329
 330         keys_delete(request_keys);
 331
 332         *authp = auth;
 333         return (request);
 334 }
 335
 336 static void
 337 login_send_chap_success(struct pdu *request,
 338     const struct auth *auth)
 339 {
 340         struct pdu *response;
 341         struct keys *request_keys, *response_keys;
 342         struct rchap *rchap;
 343         const char *chap_i, *chap_c;
 344         char *chap_r;
 345         int error;
 346
 347         response = login_new_response(request);
 348         login_set_nsg(response, BHSLR_STAGE_OPERATIONAL_NEGOTIATION);
 349
 350         /*
 351          * Actually, one more thing: mutual authentication.
 352          */
 353         request_keys = keys_new();
 354         keys_load(request_keys, request);
 355         chap_i = keys_find(request_keys, "CHAP_I");
 356         chap_c = keys_find(request_keys, "CHAP_C");
 357         if (chap_i != NULL || chap_c != NULL) {
 358                 if (chap_i == NULL) {
 359                         login_send_error(request, 0x02, 0x07);
 360                         log_errx(1, "initiator requested target "
 361                             "authentication, but didn't send CHAP_I");
 362                 }
 363                 if (chap_c == NULL) {
 364                         login_send_error(request, 0x02, 0x07);
 365                         log_errx(1, "initiator requested target "
 366                             "authentication, but didn't send CHAP_C");
 367                 }
 368                 if (auth->a_auth_group->ag_type != AG_TYPE_CHAP_MUTUAL) {
 369                         login_send_error(request, 0x02, 0x01);
 370                         log_errx(1, "initiator requests target authentication "
 371                             "for user \"%s\", but mutual user/secret "
 372                             "is not set", auth->a_user);
 373                 }
 374
 375                 log_debugx("performing mutual authentication as user \"%s\"",
 376                     auth->a_mutual_user);
 377
 378                 rchap = rchap_new(auth->a_mutual_secret);
 379                 error = rchap_receive(rchap, chap_i, chap_c);
 380                 if (error != 0) {
 381                         login_send_error(request, 0x02, 0x07);
 382                         log_errx(1, "received CHAP Login PDU with malformed "
 383                             "CHAP_I or CHAP_C");
 384                 }
 385                 chap_r = rchap_get_response(rchap);
 386                 rchap_delete(rchap);
 387                 response_keys = keys_new();
 388                 keys_add(response_keys, "CHAP_N", auth->a_mutual_user);
 389                 keys_add(response_keys, "CHAP_R", chap_r);
 390                 free(chap_r);
 391                 keys_save(response_keys, response);
 392                 keys_delete(response_keys);
 393         } else {
 394                 log_debugx("initiator did not request target authentication");
 395         }
 396
 397         keys_delete(request_keys);
 398         pdu_send(response);
 399         pdu_delete(response);
 400 }
 401
 402 static void
 403 login_chap(struct connection *conn, struct auth_group *ag)
 404 {
 405         const struct auth *auth;
 406         struct chap *chap;
 407         struct pdu *request;
 408
 409         /*
 410          * Receive CHAP_A PDU.
 411          */
 412         log_debugx("beginning CHAP authentication; waiting for CHAP_A");
 413         request = login_receive_chap_a(conn);
 414
 415         /*
 416          * Generate the challenge.
 417          */
 418         chap = chap_new();
 419
 420         /*
 421          * Send the challenge.
 422          */
 423         log_debugx("sending CHAP_C, binary challenge size is %zd bytes",
 424             sizeof(chap->chap_challenge));
 425         login_send_chap_c(request, chap);
 426         pdu_delete(request);
 427
 428         /*
 429          * Receive CHAP_N/CHAP_R PDU and authenticate.
 430          */
 431         log_debugx("waiting for CHAP_N/CHAP_R");
 432         request = login_receive_chap_r(conn, ag, chap, &auth);
 433
 434         /*
 435          * Yay, authentication succeeded!
 436          */
 437         log_debugx("authentication succeeded for user \"%s\"; "
 438             "transitioning to Negotiation Phase", auth->a_user);
 439         login_send_chap_success(request, auth);
 440         pdu_delete(request);
 441
 442         /*
 443          * Leave username and CHAP information for discovery().
 444          */
 445         conn->conn_user = auth->a_user;
 446         conn->conn_chap = chap;
 447 }
 448
 449 static void
 450 login_negotiate_key(struct pdu *request, const char *name,
 451     const char *value, bool skipped_security, struct keys *response_keys)
 452 {
 453         int which;
 454         size_t tmp;
 455         struct connection *conn;
 456
 457         conn = request->pdu_connection;
 458
 459         if (strcmp(name, "InitiatorName") == 0) {
 460                 if (!skipped_security)
 461                         log_errx(1, "initiator resent InitiatorName");
 462         } else if (strcmp(name, "SessionType") == 0) {
 463                 if (!skipped_security)
 464                         log_errx(1, "initiator resent SessionType");
 465         } else if (strcmp(name, "TargetName") == 0) {
 466                 if (!skipped_security)
 467                         log_errx(1, "initiator resent TargetName");
 468         } else if (strcmp(name, "InitiatorAlias") == 0) {
 469                 if (conn->conn_initiator_alias != NULL)
 470                         free(conn->conn_initiator_alias);
 471                 conn->conn_initiator_alias = checked_strdup(value);
 472         } else if (strcmp(value, "Irrelevant") == 0) {
 473                 /* Ignore. */
 474         } else if (strcmp(name, "HeaderDigest") == 0) {
 475                 /*
 476                  * We don't handle digests for discovery sessions.
 477                  */
 478                 if (conn->conn_session_type == CONN_SESSION_TYPE_DISCOVERY) {
 479                         log_debugx("discovery session; digests disabled");
 480                         keys_add(response_keys, name, "None");
 481                         return;
 482                 }
 483
 484                 which = login_list_prefers(value, "CRC32C", "None");
 485                 switch (which) {
 486                 case 1:
 487                         log_debugx("initiator prefers CRC32C "
 488                             "for header digest; we'll use it");
 489                         conn->conn_header_digest = CONN_DIGEST_CRC32C;
 490                         keys_add(response_keys, name, "CRC32C");
 491                         break;
 492                 case 2:
 493                         log_debugx("initiator prefers not to do "
 494                             "header digest; we'll comply");
 495                         keys_add(response_keys, name, "None");
 496                         break;
 497                 default:
 498                         log_warnx("initiator sent unrecognized "
 499                             "HeaderDigest value \"%s\"; will use None", value);
 500                         keys_add(response_keys, name, "None");
 501                         break;
 502                 }
 503         } else if (strcmp(name, "DataDigest") == 0) {
 504                 if (conn->conn_session_type == CONN_SESSION_TYPE_DISCOVERY) {
 505                         log_debugx("discovery session; digests disabled");
 506                         keys_add(response_keys, name, "None");
 507                         return;
 508                 }
 509
 510                 which = login_list_prefers(value, "CRC32C", "None");
 511                 switch (which) {
 512                 case 1:
 513                         log_debugx("initiator prefers CRC32C "
 514                             "for data digest; we'll use it");
 515                         conn->conn_data_digest = CONN_DIGEST_CRC32C;
 516                         keys_add(response_keys, name, "CRC32C");
 517                         break;
 518                 case 2:
 519                         log_debugx("initiator prefers not to do "
 520                             "data digest; we'll comply");
 521                         keys_add(response_keys, name, "None");
 522                         break;
 523                 default:
 524                         log_warnx("initiator sent unrecognized "
 525                             "DataDigest value \"%s\"; will use None", value);
 526                         keys_add(response_keys, name, "None");
 527                         break;
 528                 }
 529         } else if (strcmp(name, "MaxConnections") == 0) {
 530                 keys_add(response_keys, name, "1");
 531         } else if (strcmp(name, "InitialR2T") == 0) {
 532                 keys_add(response_keys, name, "Yes");
 533         } else if (strcmp(name, "ImmediateData") == 0) {
 534                 if (conn->conn_session_type == CONN_SESSION_TYPE_DISCOVERY) {
 535                         log_debugx("discovery session; ImmediateData irrelevant");
 536                         keys_add(response_keys, name, "Irrelevant");
 537                 } else {
 538                         if (strcmp(value, "Yes") == 0) {
 539                                 conn->conn_immediate_data = true;
 540                                 keys_add(response_keys, name, "Yes");
 541                         } else {
 542                                 conn->conn_immediate_data = false;
 543                                 keys_add(response_keys, name, "No");
 544                         }
 545                 }
 546         } else if (strcmp(name, "MaxRecvDataSegmentLength") == 0) {
 547                 tmp = strtoul(value, NULL, 10);
 548                 if (tmp <= 0) {
 549                         login_send_error(request, 0x02, 0x00);
 550                         log_errx(1, "received invalid "
 551                             "MaxRecvDataSegmentLength");
 552                 }
 553
 554                 /*
 555                  * MaxRecvDataSegmentLength is a direction-specific parameter.
 556                  * We'll limit our _send_ to what the initiator can handle but
 557                  * our MaxRecvDataSegmentLength is not influenced by the
 558                  * initiator in any way.
 559                  */
 560                 if ((int)tmp > conn->conn_max_send_data_segment_limit) {
 561                         log_debugx("capping MaxRecvDataSegmentLength "
 562                             "from %zd to %d", tmp,
 563                             conn->conn_max_send_data_segment_limit);
 564                         tmp = conn->conn_max_send_data_segment_limit;
 565                 }
 566                 conn->conn_max_send_data_segment_length = tmp;
 567                 conn->conn_max_recv_data_segment_length =
 568                     conn->conn_max_recv_data_segment_limit;
 569                 keys_add_int(response_keys, name,
 570                     conn->conn_max_recv_data_segment_length);
 571         } else if (strcmp(name, "MaxBurstLength") == 0) {
 572                 tmp = strtoul(value, NULL, 10);
 573                 if (tmp <= 0) {
 574                         login_send_error(request, 0x02, 0x00);
 575                         log_errx(1, "received invalid MaxBurstLength");
 576                 }
 577                 if ((int)tmp > conn->conn_max_burst_limit) {
 578                         log_debugx("capping MaxBurstLength from %zd to %d",
 579                             tmp, conn->conn_max_burst_limit);
 580                         tmp = conn->conn_max_burst_limit;
 581                 }
 582                 conn->conn_max_burst_length = tmp;
 583                 keys_add_int(response_keys, name, tmp);
 584         } else if (strcmp(name, "FirstBurstLength") == 0) {
 585                 tmp = strtoul(value, NULL, 10);
 586                 if (tmp <= 0) {
 587                         login_send_error(request, 0x02, 0x00);
 588                         log_errx(1, "received invalid FirstBurstLength");
 589                 }
 590                 if ((int)tmp > conn->conn_first_burst_limit) {
 591                         log_debugx("capping FirstBurstLength from %zd to %d",
 592                             tmp, conn->conn_first_burst_limit);
 593                         tmp = conn->conn_first_burst_limit;
 594                 }
 595                 conn->conn_first_burst_length = tmp;
 596                 keys_add_int(response_keys, name, tmp);
 597         } else if (strcmp(name, "DefaultTime2Wait") == 0) {
 598                 keys_add(response_keys, name, value);
 599         } else if (strcmp(name, "DefaultTime2Retain") == 0) {
 600                 keys_add(response_keys, name, "0");
 601         } else if (strcmp(name, "MaxOutstandingR2T") == 0) {
 602                 keys_add(response_keys, name, "1");
 603         } else if (strcmp(name, "DataPDUInOrder") == 0) {
 604                 keys_add(response_keys, name, "Yes");
 605         } else if (strcmp(name, "DataSequenceInOrder") == 0) {
 606                 keys_add(response_keys, name, "Yes");
 607         } else if (strcmp(name, "ErrorRecoveryLevel") == 0) {
 608                 keys_add(response_keys, name, "0");
 609         } else if (strcmp(name, "OFMarker") == 0) {
 610                 keys_add(response_keys, name, "No");
 611         } else if (strcmp(name, "IFMarker") == 0) {
 612                 keys_add(response_keys, name, "No");
 613         } else if (strcmp(name, "iSCSIProtocolLevel") == 0) {
 614                 tmp = strtoul(value, NULL, 10);
 615                 if (tmp > 2)
 616                         tmp = 2;
 617                 keys_add_int(response_keys, name, tmp);
 618         } else {
 619                 log_debugx("unknown key \"%s\"; responding "
 620                     "with NotUnderstood", name);
 621                 keys_add(response_keys, name, "NotUnderstood");
 622         }
 623 }
 624
 625 static void
 626 login_redirect(struct pdu *request, const char *target_address)
 627 {
 628         struct pdu *response;
 629         struct iscsi_bhs_login_response *bhslr2;
 630         struct keys *response_keys;
 631
 632         response = login_new_response(request);
 633         login_set_csg(response, login_csg(request));
 634         bhslr2 = (struct iscsi_bhs_login_response *)response->pdu_bhs;
 635         bhslr2->bhslr_status_class = 0x01;
 636         bhslr2->bhslr_status_detail = 0x01;
 637
 638         response_keys = keys_new();
 639         keys_add(response_keys, "TargetAddress", target_address);
 640
 641         keys_save(response_keys, response);
 642         pdu_send(response);
 643         pdu_delete(response);
 644         keys_delete(response_keys);
 645 }
 646
 647 static bool
 648 login_portal_redirect(struct connection *conn, struct pdu *request)
 649 {
 650         const struct portal_group *pg;
 651
 652         pg = conn->conn_portal->p_portal_group;
 653         if (pg->pg_redirection == NULL)
 654                 return (false);
 655
 656         log_debugx("portal-group \"%s\" configured to redirect to %s",
 657             pg->pg_name, pg->pg_redirection);
 658         login_redirect(request, pg->pg_redirection);
 659
 660         return (true);
 661 }
 662
 663 static bool
 664 login_target_redirect(struct connection *conn, struct pdu *request)
 665 {
 666         const char *target_address;
 667
 668         assert(conn->conn_portal->p_portal_group->pg_redirection == NULL);
 669
 670         if (conn->conn_target == NULL)
 671                 return (false);
 672
 673         target_address = conn->conn_target->t_redirection;
 674         if (target_address == NULL)
 675                 return (false);
 676
 677         log_debugx("target \"%s\" configured to redirect to %s",
 678           conn->conn_target->t_name, target_address);
 679         login_redirect(request, target_address);
 680
 681         return (true);
 682 }
 683
 684 static void
 685 login_negotiate(struct connection *conn, struct pdu *request)
 686 {
 687         struct pdu *response;
 688         struct iscsi_bhs_login_response *bhslr2;
 689         struct keys *request_keys, *response_keys;
 690         int i;
 691         bool redirected, skipped_security;
 692
 693         if (conn->conn_session_type == CONN_SESSION_TYPE_NORMAL) {
 694                 /*
 695                  * Query the kernel for various size limits.  In case of
 696                  * offload, it depends on hardware capabilities.
 697                  */
 698                 assert(conn->conn_target != NULL);
 699                 conn->conn_max_recv_data_segment_limit = (1 << 24) - 1;
 700                 conn->conn_max_send_data_segment_limit = (1 << 24) - 1;
 701                 conn->conn_max_burst_limit = (1 << 24) - 1;
 702                 conn->conn_first_burst_limit = (1 << 24) - 1;
 703                 kernel_limits(conn->conn_portal->p_portal_group->pg_offload,
 704                     &conn->conn_max_recv_data_segment_limit,
 705                     &conn->conn_max_send_data_segment_limit,
 706                     &conn->conn_max_burst_limit,
 707                     &conn->conn_first_burst_limit);
 708
 709                 /* We expect legal, usable values at this point. */
 710                 assert(conn->conn_max_recv_data_segment_limit >= 512);
 711                 assert(conn->conn_max_recv_data_segment_limit < (1 << 24));
 712                 assert(conn->conn_max_send_data_segment_limit >= 512);
 713                 assert(conn->conn_max_send_data_segment_limit < (1 << 24));
 714                 assert(conn->conn_max_burst_limit >= 512);
 715                 assert(conn->conn_max_burst_limit < (1 << 24));
 716                 assert(conn->conn_first_burst_limit >= 512);
 717                 assert(conn->conn_first_burst_limit < (1 << 24));
 718                 assert(conn->conn_first_burst_limit <=
 719                     conn->conn_max_burst_limit);
 720
 721                 /*
 722                  * Limit default send length in case it won't be negotiated.
 723                  * We can't do it for other limits, since they may affect both
 724                  * sender and receiver operation, and we must obey defaults.
 725                  */
 726                 if (conn->conn_max_send_data_segment_limit <
 727                     conn->conn_max_send_data_segment_length) {
 728                         conn->conn_max_send_data_segment_length =
 729                             conn->conn_max_send_data_segment_limit;
 730                 }
 731         } else {
 732                 conn->conn_max_recv_data_segment_limit =
 733                     MAX_DATA_SEGMENT_LENGTH;
 734                 conn->conn_max_send_data_segment_limit =
 735                     MAX_DATA_SEGMENT_LENGTH;
 736         }
 737
 738         if (request == NULL) {
 739                 log_debugx("beginning operational parameter negotiation; "
 740                     "waiting for Login PDU");
 741                 request = login_receive(conn, false);
 742                 skipped_security = false;
 743         } else
 744                 skipped_security = true;
 745
 746         /*
 747          * RFC 3720, 10.13.5.  Status-Class and Status-Detail, says
 748          * the redirection SHOULD be accepted by the initiator before
 749          * authentication, but MUST be be accepted afterwards; that's
 750          * why we're doing it here and not earlier.
 751          */
 752         redirected = login_target_redirect(conn, request);
 753         if (redirected) {
 754                 log_debugx("initiator redirected; exiting");
 755                 exit(0);
 756         }
 757
 758         request_keys = keys_new();
 759         keys_load(request_keys, request);
 760
 761         response = login_new_response(request);
 762         bhslr2 = (struct iscsi_bhs_login_response *)response->pdu_bhs;
 763         bhslr2->bhslr_tsih = htons(0xbadd);
 764         login_set_csg(response, BHSLR_STAGE_OPERATIONAL_NEGOTIATION);
 765         login_set_nsg(response, BHSLR_STAGE_FULL_FEATURE_PHASE);
 766         response_keys = keys_new();
 767
 768         if (skipped_security &&
 769             conn->conn_session_type == CONN_SESSION_TYPE_NORMAL) {
 770                 if (conn->conn_target->t_alias != NULL)
 771                         keys_add(response_keys,
 772                             "TargetAlias", conn->conn_target->t_alias);
 773                 keys_add_int(response_keys, "TargetPortalGroupTag",
 774                     conn->conn_portal->p_portal_group->pg_tag);
 775         }
 776
 777         for (i = 0; i < KEYS_MAX; i++) {
 778                 if (request_keys->keys_names[i] == NULL)
 779                         break;
 780
 781                 login_negotiate_key(request, request_keys->keys_names[i],
 782                     request_keys->keys_values[i], skipped_security,
 783                     response_keys);
 784         }
 785
 786         /*
 787          * We'd started with usable values at our end.  But a bad initiator
 788          * could have presented a large FirstBurstLength and then a smaller
 789          * MaxBurstLength (in that order) and because we process the key/value
 790          * pairs in the order they are in the request we might have ended up
 791          * with illegal values here.
 792          */
 793         if (conn->conn_session_type == CONN_SESSION_TYPE_NORMAL &&
 794             conn->conn_first_burst_length > conn->conn_max_burst_length) {
 795                 log_errx(1, "initiator sent FirstBurstLength > MaxBurstLength");
 796         }
 797
 798         log_debugx("operational parameter negotiation done; "
 799             "transitioning to Full Feature Phase");
 800
 801         keys_save(response_keys, response);
 802         pdu_send(response);
 803         pdu_delete(response);
 804         keys_delete(response_keys);
 805         pdu_delete(request);
 806         keys_delete(request_keys);
 807 }
 808
 809 static void
 810 login_wait_transition(struct connection *conn)
 811 {
 812         struct pdu *request, *response;
 813         struct iscsi_bhs_login_request *bhslr;
 814
 815         log_debugx("waiting for state transition request");
 816         request = login_receive(conn, false);
 817         bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs;
 818         if ((bhslr->bhslr_flags & BHSLR_FLAGS_TRANSIT) == 0) {
 819                 login_send_error(request, 0x02, 0x00);
 820                 log_errx(1, "got no \"T\" flag after answering AuthMethod");
 821         }
 822
 823         log_debugx("got state transition request");
 824         response = login_new_response(request);
 825         pdu_delete(request);
 826         login_set_nsg(response, BHSLR_STAGE_OPERATIONAL_NEGOTIATION);
 827         pdu_send(response);
 828         pdu_delete(response);
 829
 830         login_negotiate(conn, NULL);
 831 }
 832
 833 void
 834 login(struct connection *conn)
 835 {
 836         struct pdu *request, *response;
 837         struct iscsi_bhs_login_request *bhslr;
 838         struct keys *request_keys, *response_keys;
 839         struct auth_group *ag;
 840         struct portal_group *pg;
 841         const char *initiator_name, *initiator_alias, *session_type,
 842             *target_name, *auth_method;
 843         bool redirected, fail, trans;
 844
 845         /*
 846          * Handle the initial Login Request - figure out required authentication
 847          * method and either transition to the next phase, if no authentication
 848          * is required, or call appropriate authentication code.
 849          */
 850         log_debugx("beginning Login Phase; waiting for Login PDU");
 851         request = login_receive(conn, true);
 852         bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs;
 853         if (bhslr->bhslr_tsih != 0) {
 854                 login_send_error(request, 0x02, 0x0a);
 855                 log_errx(1, "received Login PDU with non-zero TSIH");
 856         }
 857
 858         pg = conn->conn_portal->p_portal_group;
 859
 860         memcpy(conn->conn_initiator_isid, bhslr->bhslr_isid,
 861             sizeof(conn->conn_initiator_isid));
 862
 863         /*
 864          * XXX: Implement the C flag some day.
 865          */
 866         request_keys = keys_new();
 867         keys_load(request_keys, request);
 868
 869         assert(conn->conn_initiator_name == NULL);
 870         initiator_name = keys_find(request_keys, "InitiatorName");
 871         if (initiator_name == NULL) {
 872                 login_send_error(request, 0x02, 0x07);
 873                 log_errx(1, "received Login PDU without InitiatorName");
 874         }
 875         if (valid_iscsi_name(initiator_name) == false) {
 876                 login_send_error(request, 0x02, 0x00);
 877                 log_errx(1, "received Login PDU with invalid InitiatorName");
 878         }
 879         conn->conn_initiator_name = checked_strdup(initiator_name);
 880         log_set_peer_name(conn->conn_initiator_name);
 881         setproctitle("%s (%s)", conn->conn_initiator_addr, conn->conn_initiator_name);
 882
 883         redirected = login_portal_redirect(conn, request);
 884         if (redirected) {
 885                 log_debugx("initiator redirected; exiting");
 886                 exit(0);
 887         }
 888
 889         initiator_alias = keys_find(request_keys, "InitiatorAlias");
 890         if (initiator_alias != NULL)
 891                 conn->conn_initiator_alias = checked_strdup(initiator_alias);
 892
 893         assert(conn->conn_session_type == CONN_SESSION_TYPE_NONE);
 894         session_type = keys_find(request_keys, "SessionType");
 895         if (session_type != NULL) {
 896                 if (strcmp(session_type, "Normal") == 0) {
 897                         conn->conn_session_type = CONN_SESSION_TYPE_NORMAL;
 898                 } else if (strcmp(session_type, "Discovery") == 0) {
 899                         conn->conn_session_type = CONN_SESSION_TYPE_DISCOVERY;
 900                 } else {
 901                         login_send_error(request, 0x02, 0x00);
 902                         log_errx(1, "received Login PDU with invalid "
 903                             "SessionType \"%s\"", session_type);
 904                 }
 905         } else
 906                 conn->conn_session_type = CONN_SESSION_TYPE_NORMAL;
 907
 908         assert(conn->conn_target == NULL);
 909         if (conn->conn_session_type == CONN_SESSION_TYPE_NORMAL) {
 910                 target_name = keys_find(request_keys, "TargetName");
 911                 if (target_name == NULL) {
 912                         login_send_error(request, 0x02, 0x07);
 913                         log_errx(1, "received Login PDU without TargetName");
 914                 }
 915
 916                 conn->conn_port = port_find_in_pg(pg, target_name);
 917                 if (conn->conn_port == NULL) {
 918                         login_send_error(request, 0x02, 0x03);
 919                         log_errx(1, "requested target \"%s\" not found",
 920                             target_name);
 921                 }
 922                 conn->conn_target = conn->conn_port->p_target;
 923         }
 924
 925         /*
 926          * At this point we know what kind of authentication we need.
 927          */
 928         if (conn->conn_session_type == CONN_SESSION_TYPE_NORMAL) {
 929                 ag = conn->conn_port->p_auth_group;
 930                 if (ag == NULL)
 931                         ag = conn->conn_target->t_auth_group;
 932                 if (ag->ag_name != NULL) {
 933                         log_debugx("initiator requests to connect "
 934                             "to target \"%s\"; auth-group \"%s\"",
 935                             conn->conn_target->t_name,
 936                             ag->ag_name);
 937                 } else {
 938                         log_debugx("initiator requests to connect "
 939                             "to target \"%s\"", conn->conn_target->t_name);
 940                 }
 941         } else {
 942                 assert(conn->conn_session_type == CONN_SESSION_TYPE_DISCOVERY);
 943                 ag = pg->pg_discovery_auth_group;
 944                 if (ag->ag_name != NULL) {
 945                         log_debugx("initiator requests "
 946                             "discovery session; auth-group \"%s\"", ag->ag_name);
 947                 } else {
 948                         log_debugx("initiator requests discovery session");
 949                 }
 950         }
 951
 952         if (ag->ag_type == AG_TYPE_DENY) {
 953                 login_send_error(request, 0x02, 0x01);
 954                 log_errx(1, "auth-type is \"deny\"");
 955         }
 956
 957         if (ag->ag_type == AG_TYPE_UNKNOWN) {
 958                 /*
 959                  * This can happen with empty auth-group.
 960                  */
 961                 login_send_error(request, 0x02, 0x01);
 962                 log_errx(1, "auth-type not set, denying access");
 963         }
 964
 965         /*
 966          * Enforce initiator-name and initiator-portal.
 967          */
 968         if (auth_name_check(ag, initiator_name) != 0) {
 969                 login_send_error(request, 0x02, 0x02);
 970                 log_errx(1, "initiator does not match allowed initiator names");
 971         }
 972
 973         if (auth_portal_check(ag, &conn->conn_initiator_sa) != 0) {
 974                 login_send_error(request, 0x02, 0x02);
 975                 log_errx(1, "initiator does not match allowed "
 976                     "initiator portals");
 977         }
 978
 979         /*
 980          * Let's see if the initiator intends to do any kind of authentication
 981          * at all.
 982          */
 983         if (login_csg(request) == BHSLR_STAGE_OPERATIONAL_NEGOTIATION) {
 984                 if (ag->ag_type != AG_TYPE_NO_AUTHENTICATION) {
 985                         login_send_error(request, 0x02, 0x01);
 986                         log_errx(1, "initiator skipped the authentication, "
 987                             "but authentication is required");
 988                 }
 989
 990                 keys_delete(request_keys);
 991
 992                 log_debugx("initiator skipped the authentication, "
 993                     "and we don't need it; proceeding with negotiation");
 994                 login_negotiate(conn, request);
 995                 return;
 996         }
 997
 998         fail = false;
 999         response = login_new_response(request);
1000         response_keys = keys_new();
1001         trans = (bhslr->bhslr_flags & BHSLR_FLAGS_TRANSIT) != 0;
1002         auth_method = keys_find(request_keys, "AuthMethod");
1003         if (ag->ag_type == AG_TYPE_NO_AUTHENTICATION) {
1004                 log_debugx("authentication not required");
1005                 if (auth_method == NULL ||
1006                     login_list_contains(auth_method, "None")) {
1007                         keys_add(response_keys, "AuthMethod", "None");
1008                 } else {
1009                         log_warnx("initiator requests "
1010                             "AuthMethod \"%s\" instead of \"None\"",
1011                             auth_method);
1012                         keys_add(response_keys, "AuthMethod", "Reject");
1013                 }
1014                 if (trans)
1015                         login_set_nsg(response, BHSLR_STAGE_OPERATIONAL_NEGOTIATION);
1016         } else {
1017                 log_debugx("CHAP authentication required");
1018                 if (auth_method == NULL ||
1019                     login_list_contains(auth_method, "CHAP")) {
1020                         keys_add(response_keys, "AuthMethod", "CHAP");
1021                 } else {
1022                         log_warnx("initiator requests unsupported "
1023                             "AuthMethod \"%s\" instead of \"CHAP\"",
1024                             auth_method);
1025                         keys_add(response_keys, "AuthMethod", "Reject");
1026                         fail = true;
1027                 }
1028         }
1029         if (conn->conn_session_type == CONN_SESSION_TYPE_NORMAL) {
1030                 if (conn->conn_target->t_alias != NULL)
1031                         keys_add(response_keys,
1032                             "TargetAlias", conn->conn_target->t_alias);
1033                 keys_add_int(response_keys,
1034                     "TargetPortalGroupTag", pg->pg_tag);
1035         }
1036         keys_save(response_keys, response);
1037
1038         pdu_send(response);
1039         pdu_delete(response);
1040         keys_delete(response_keys);
1041         pdu_delete(request);
1042         keys_delete(request_keys);
1043
1044         if (fail) {
1045                 log_debugx("sent reject for AuthMethod; exiting");
1046                 exit(1);
1047         }
1048
1049         if (ag->ag_type != AG_TYPE_NO_AUTHENTICATION) {
1050                 login_chap(conn, ag);
1051                 login_negotiate(conn, NULL);
1052         } else if (trans) {
1053                 login_negotiate(conn, NULL);
1054         } else {
1055                 login_wait_transition(conn);
1056         }
1057 }