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