usr.sbin/ctld/login.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-2-Clause
   3  *
   4  * Copyright (c) 2012 The FreeBSD Foundation
   5  *
   6  * This software was developed by Edward Tomasz Napierala under sponsorship
   7  * from the FreeBSD Foundation.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in the
  16  *    documentation and/or other materials provided with the distribution.
  17  *
  18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  28  * SUCH DAMAGE.
  29  *
  30  */
  31
  32 #include <sys/cdefs.h>
  33 #include <assert.h>
  34 #include <stdbool.h>
  35 #include <stdlib.h>
  36 #include <string.h>
  37 #include <unistd.h>
  38 #include <netinet/in.h>
  39
  40 #include "ctld.h"
  41 #include "iscsi_proto.h"
  42
  43 static void login_send_error(struct pdu *request,
  44     char class, char detail);
  45
  46 static void
  47 login_set_nsg(struct pdu *response, int nsg)
  48 {
  49         struct iscsi_bhs_login_response *bhslr;
  50
  51         assert(nsg == BHSLR_STAGE_SECURITY_NEGOTIATION ||
  52             nsg == BHSLR_STAGE_OPERATIONAL_NEGOTIATION ||
  53             nsg == BHSLR_STAGE_FULL_FEATURE_PHASE);
  54
  55         bhslr = (struct iscsi_bhs_login_response *)response->pdu_bhs;
  56
  57         bhslr->bhslr_flags &= 0xFC;
  58         bhslr->bhslr_flags |= nsg;
  59         bhslr->bhslr_flags |= BHSLR_FLAGS_TRANSIT;
  60 }
  61
  62 static int
  63 login_csg(const struct pdu *request)
  64 {
  65         struct iscsi_bhs_login_request *bhslr;
  66
  67         bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs;
  68
  69         return ((bhslr->bhslr_flags & 0x0C) >> 2);
  70 }
  71
  72 static void
  73 login_set_csg(struct pdu *response, int csg)
  74 {
  75         struct iscsi_bhs_login_response *bhslr;
  76
  77         assert(csg == BHSLR_STAGE_SECURITY_NEGOTIATION ||
  78             csg == BHSLR_STAGE_OPERATIONAL_NEGOTIATION ||
  79             csg == BHSLR_STAGE_FULL_FEATURE_PHASE);
  80
  81         bhslr = (struct iscsi_bhs_login_response *)response->pdu_bhs;
  82
  83         bhslr->bhslr_flags &= 0xF3;
  84         bhslr->bhslr_flags |= csg << 2;
  85 }
  86
  87 static struct pdu *
  88 login_receive(struct connection *conn, bool initial)
  89 {
  90         struct pdu *request;
  91         struct iscsi_bhs_login_request *bhslr;
  92
  93         request = pdu_new(conn);
  94         pdu_receive(request);
  95         if ((request->pdu_bhs->bhs_opcode & ~ISCSI_BHS_OPCODE_IMMEDIATE) !=
  96             ISCSI_BHS_OPCODE_LOGIN_REQUEST) {
  97                 /*
  98                  * The first PDU in session is special - if we receive any PDU
  99                  * different than login request, we have to drop the connection
 100                  * without sending response ("A target receiving any PDU
 101                  * except a Login request before the Login Phase is started MUST
 102                  * immediately terminate the connection on which the PDU
 103                  * was received.")
 104                  */
 105                 if (initial == false)
 106                         login_send_error(request, 0x02, 0x0b);
 107                 log_errx(1, "protocol error: received invalid opcode 0x%x",
 108                     request->pdu_bhs->bhs_opcode);
 109         }
 110         bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs;
 111         /*
 112          * XXX: Implement the C flag some day.
 113          */
 114         if ((bhslr->bhslr_flags & BHSLR_FLAGS_CONTINUE) != 0) {
 115                 login_send_error(request, 0x03, 0x00);
 116                 log_errx(1, "received Login PDU with unsupported \"C\" flag");
 117         }
 118         if (bhslr->bhslr_version_max != 0x00) {
 119                 login_send_error(request, 0x02, 0x05);
 120                 log_errx(1, "received Login PDU with unsupported "
 121                     "Version-max 0x%x", bhslr->bhslr_version_max);
 122         }
 123         if (bhslr->bhslr_version_min != 0x00) {
 124                 login_send_error(request, 0x02, 0x05);
 125                 log_errx(1, "received Login PDU with unsupported "
 126                     "Version-min 0x%x", bhslr->bhslr_version_min);
 127         }
 128         if (initial == false &&
 129             ISCSI_SNLT(ntohl(bhslr->bhslr_cmdsn), conn->conn_cmdsn)) {
 130                 login_send_error(request, 0x02, 0x00);
 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, 0x00);
 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_pdu(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_pdu(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_pdu(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_pdu(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_pdu(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 ctld_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->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->conn, ag, chap, &auth);
 432
 433         /*
 434          * Yay, authentication succeeded!
 435          */
 436         log_debugx("authentication succeeded for user \"%s\"; "
 437             "transitioning to operational parameter negotiation", 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 ctld_connection *conn;
 455
 456         conn = (struct ctld_connection *)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.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.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.conn_immediate_data = true;
 539                                 keys_add(response_keys, name, "Yes");
 540                         } else {
 541                                 conn->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
 553                 /*
 554                  * MaxRecvDataSegmentLength is a direction-specific parameter.
 555                  * We'll limit our _send_ to what the initiator can handle but
 556                  * our MaxRecvDataSegmentLength is not influenced by the
 557                  * initiator in any way.
 558                  */
 559                 if ((int)tmp > conn->conn_max_send_data_segment_limit) {
 560                         log_debugx("capping MaxRecvDataSegmentLength "
 561                             "from %zd to %d", tmp,
 562                             conn->conn_max_send_data_segment_limit);
 563                         tmp = conn->conn_max_send_data_segment_limit;
 564                 }
 565                 conn->conn.conn_max_send_data_segment_length = tmp;
 566         } else if (strcmp(name, "MaxBurstLength") == 0) {
 567                 tmp = strtoul(value, NULL, 10);
 568                 if (tmp <= 0) {
 569                         login_send_error(request, 0x02, 0x00);
 570                         log_errx(1, "received invalid MaxBurstLength");
 571                 }
 572                 if ((int)tmp > conn->conn_max_burst_limit) {
 573                         log_debugx("capping MaxBurstLength from %zd to %d",
 574                             tmp, conn->conn_max_burst_limit);
 575                         tmp = conn->conn_max_burst_limit;
 576                 }
 577                 conn->conn.conn_max_burst_length = tmp;
 578                 keys_add_int(response_keys, name, tmp);
 579         } else if (strcmp(name, "FirstBurstLength") == 0) {
 580                 tmp = strtoul(value, NULL, 10);
 581                 if (tmp <= 0) {
 582                         login_send_error(request, 0x02, 0x00);
 583                         log_errx(1, "received invalid FirstBurstLength");
 584                 }
 585                 if ((int)tmp > conn->conn_first_burst_limit) {
 586                         log_debugx("capping FirstBurstLength from %zd to %d",
 587                             tmp, conn->conn_first_burst_limit);
 588                         tmp = conn->conn_first_burst_limit;
 589                 }
 590                 conn->conn.conn_first_burst_length = tmp;
 591                 keys_add_int(response_keys, name, tmp);
 592         } else if (strcmp(name, "DefaultTime2Wait") == 0) {
 593                 keys_add(response_keys, name, value);
 594         } else if (strcmp(name, "DefaultTime2Retain") == 0) {
 595                 keys_add(response_keys, name, "0");
 596         } else if (strcmp(name, "MaxOutstandingR2T") == 0) {
 597                 keys_add(response_keys, name, "1");
 598         } else if (strcmp(name, "DataPDUInOrder") == 0) {
 599                 keys_add(response_keys, name, "Yes");
 600         } else if (strcmp(name, "DataSequenceInOrder") == 0) {
 601                 keys_add(response_keys, name, "Yes");
 602         } else if (strcmp(name, "ErrorRecoveryLevel") == 0) {
 603                 keys_add(response_keys, name, "0");
 604         } else if (strcmp(name, "OFMarker") == 0) {
 605                 keys_add(response_keys, name, "No");
 606         } else if (strcmp(name, "IFMarker") == 0) {
 607                 keys_add(response_keys, name, "No");
 608         } else if (strcmp(name, "iSCSIProtocolLevel") == 0) {
 609                 tmp = strtoul(value, NULL, 10);
 610                 if (tmp > 2)
 611                         tmp = 2;
 612                 keys_add_int(response_keys, name, tmp);
 613         } else {
 614                 log_debugx("unknown key \"%s\"; responding "
 615                     "with NotUnderstood", name);
 616                 keys_add(response_keys, name, "NotUnderstood");
 617         }
 618 }
 619
 620 static void
 621 login_redirect(struct pdu *request, const char *target_address)
 622 {
 623         struct pdu *response;
 624         struct iscsi_bhs_login_response *bhslr2;
 625         struct keys *response_keys;
 626
 627         response = login_new_response(request);
 628         login_set_csg(response, login_csg(request));
 629         bhslr2 = (struct iscsi_bhs_login_response *)response->pdu_bhs;
 630         bhslr2->bhslr_status_class = 0x01;
 631         bhslr2->bhslr_status_detail = 0x01;
 632
 633         response_keys = keys_new();
 634         keys_add(response_keys, "TargetAddress", target_address);
 635
 636         keys_save_pdu(response_keys, response);
 637         pdu_send(response);
 638         pdu_delete(response);
 639         keys_delete(response_keys);
 640 }
 641
 642 static bool
 643 login_portal_redirect(struct ctld_connection *conn, struct pdu *request)
 644 {
 645         const struct portal_group *pg;
 646
 647         pg = conn->conn_portal->p_portal_group;
 648         if (pg->pg_redirection == NULL)
 649                 return (false);
 650
 651         log_debugx("portal-group \"%s\" configured to redirect to %s",
 652             pg->pg_name, pg->pg_redirection);
 653         login_redirect(request, pg->pg_redirection);
 654
 655         return (true);
 656 }
 657
 658 static bool
 659 login_target_redirect(struct ctld_connection *conn, struct pdu *request)
 660 {
 661         const char *target_address;
 662
 663         assert(conn->conn_portal->p_portal_group->pg_redirection == NULL);
 664
 665         if (conn->conn_target == NULL)
 666                 return (false);
 667
 668         target_address = conn->conn_target->t_redirection;
 669         if (target_address == NULL)
 670                 return (false);
 671
 672         log_debugx("target \"%s\" configured to redirect to %s",
 673           conn->conn_target->t_name, target_address);
 674         login_redirect(request, target_address);
 675
 676         return (true);
 677 }
 678
 679 static void
 680 login_negotiate(struct ctld_connection *conn, struct pdu *request)
 681 {
 682         struct pdu *response;
 683         struct iscsi_bhs_login_response *bhslr2;
 684         struct keys *request_keys, *response_keys;
 685         int i;
 686         bool redirected, skipped_security;
 687
 688         if (conn->conn_session_type == CONN_SESSION_TYPE_NORMAL) {
 689                 /*
 690                  * Query the kernel for various size limits.  In case of
 691                  * offload, it depends on hardware capabilities.
 692                  */
 693                 assert(conn->conn_target != NULL);
 694                 conn->conn_max_recv_data_segment_limit = (1 << 24) - 1;
 695                 conn->conn_max_send_data_segment_limit = (1 << 24) - 1;
 696                 conn->conn_max_burst_limit = (1 << 24) - 1;
 697                 conn->conn_first_burst_limit = (1 << 24) - 1;
 698                 kernel_limits(conn->conn_portal->p_portal_group->pg_offload,
 699                     conn->conn.conn_socket,
 700                     &conn->conn_max_recv_data_segment_limit,
 701                     &conn->conn_max_send_data_segment_limit,
 702                     &conn->conn_max_burst_limit,
 703                     &conn->conn_first_burst_limit);
 704
 705                 /* We expect legal, usable values at this point. */
 706                 assert(conn->conn_max_recv_data_segment_limit >= 512);
 707                 assert(conn->conn_max_recv_data_segment_limit < (1 << 24));
 708                 assert(conn->conn_max_send_data_segment_limit >= 512);
 709                 assert(conn->conn_max_send_data_segment_limit < (1 << 24));
 710                 assert(conn->conn_max_burst_limit >= 512);
 711                 assert(conn->conn_max_burst_limit < (1 << 24));
 712                 assert(conn->conn_first_burst_limit >= 512);
 713                 assert(conn->conn_first_burst_limit < (1 << 24));
 714                 assert(conn->conn_first_burst_limit <=
 715                     conn->conn_max_burst_limit);
 716
 717                 /*
 718                  * Limit default send length in case it won't be negotiated.
 719                  * We can't do it for other limits, since they may affect both
 720                  * sender and receiver operation, and we must obey defaults.
 721                  */
 722                 if (conn->conn_max_send_data_segment_limit <
 723                     conn->conn.conn_max_send_data_segment_length) {
 724                         conn->conn.conn_max_send_data_segment_length =
 725                             conn->conn_max_send_data_segment_limit;
 726                 }
 727         } else {
 728                 conn->conn_max_recv_data_segment_limit =
 729                     MAX_DATA_SEGMENT_LENGTH;
 730                 conn->conn_max_send_data_segment_limit =
 731                     MAX_DATA_SEGMENT_LENGTH;
 732         }
 733
 734         if (request == NULL) {
 735                 log_debugx("beginning operational parameter negotiation; "
 736                     "waiting for Login PDU");
 737                 request = login_receive(&conn->conn, false);
 738                 skipped_security = false;
 739         } else
 740                 skipped_security = true;
 741
 742         /*
 743          * RFC 3720, 10.13.5.  Status-Class and Status-Detail, says
 744          * the redirection SHOULD be accepted by the initiator before
 745          * authentication, but MUST be accepted afterwards; that's
 746          * why we're doing it here and not earlier.
 747          */
 748         redirected = login_target_redirect(conn, request);
 749         if (redirected) {
 750                 log_debugx("initiator redirected; exiting");
 751                 exit(0);
 752         }
 753
 754         request_keys = keys_new();
 755         keys_load_pdu(request_keys, request);
 756
 757         response = login_new_response(request);
 758         bhslr2 = (struct iscsi_bhs_login_response *)response->pdu_bhs;
 759         bhslr2->bhslr_tsih = htons(0xbadd);
 760         login_set_csg(response, BHSLR_STAGE_OPERATIONAL_NEGOTIATION);
 761         login_set_nsg(response, BHSLR_STAGE_FULL_FEATURE_PHASE);
 762         response_keys = keys_new();
 763
 764         if (skipped_security &&
 765             conn->conn_session_type == CONN_SESSION_TYPE_NORMAL) {
 766                 if (conn->conn_target->t_alias != NULL)
 767                         keys_add(response_keys,
 768                             "TargetAlias", conn->conn_target->t_alias);
 769                 keys_add_int(response_keys, "TargetPortalGroupTag",
 770                     conn->conn_portal->p_portal_group->pg_tag);
 771         }
 772
 773         for (i = 0; i < KEYS_MAX; i++) {
 774                 if (request_keys->keys_names[i] == NULL)
 775                         break;
 776
 777                 login_negotiate_key(request, request_keys->keys_names[i],
 778                     request_keys->keys_values[i], skipped_security,
 779                     response_keys);
 780         }
 781
 782         /*
 783          * We'd started with usable values at our end.  But a bad initiator
 784          * could have presented a large FirstBurstLength and then a smaller
 785          * MaxBurstLength (in that order) and because we process the key/value
 786          * pairs in the order they are in the request we might have ended up
 787          * with illegal values here.
 788          */
 789         if (conn->conn_session_type == CONN_SESSION_TYPE_NORMAL &&
 790             conn->conn.conn_first_burst_length >
 791             conn->conn.conn_max_burst_length) {
 792                 log_errx(1, "initiator sent FirstBurstLength > MaxBurstLength");
 793         }
 794
 795         conn->conn.conn_max_recv_data_segment_length =
 796             conn->conn_max_recv_data_segment_limit;
 797         keys_add_int(response_keys, "MaxRecvDataSegmentLength",
 798                     conn->conn.conn_max_recv_data_segment_length);
 799
 800         log_debugx("operational parameter negotiation done; "
 801             "transitioning to Full Feature Phase");
 802
 803         keys_save_pdu(response_keys, response);
 804         pdu_send(response);
 805         pdu_delete(response);
 806         keys_delete(response_keys);
 807         pdu_delete(request);
 808         keys_delete(request_keys);
 809 }
 810
 811 static void
 812 login_wait_transition(struct ctld_connection *conn)
 813 {
 814         struct pdu *request, *response;
 815         struct iscsi_bhs_login_request *bhslr;
 816
 817         log_debugx("waiting for state transition request");
 818         request = login_receive(&conn->conn, false);
 819         bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs;
 820         if ((bhslr->bhslr_flags & BHSLR_FLAGS_TRANSIT) == 0) {
 821                 login_send_error(request, 0x02, 0x00);
 822                 log_errx(1, "got no \"T\" flag after answering AuthMethod");
 823         }
 824
 825         log_debugx("got state transition request");
 826         response = login_new_response(request);
 827         pdu_delete(request);
 828         login_set_nsg(response, BHSLR_STAGE_OPERATIONAL_NEGOTIATION);
 829         pdu_send(response);
 830         pdu_delete(response);
 831
 832         login_negotiate(conn, NULL);
 833 }
 834
 835 void
 836 login(struct ctld_connection *conn)
 837 {
 838         struct pdu *request, *response;
 839         struct iscsi_bhs_login_request *bhslr;
 840         struct keys *request_keys, *response_keys;
 841         struct auth_group *ag;
 842         struct portal_group *pg;
 843         const char *initiator_name, *initiator_alias, *session_type,
 844             *target_name, *auth_method;
 845         bool redirected, fail, trans;
 846
 847         /*
 848          * Handle the initial Login Request - figure out required authentication
 849          * method and either transition to the next phase, if no authentication
 850          * is required, or call appropriate authentication code.
 851          */
 852         log_debugx("beginning Login Phase; waiting for Login PDU");
 853         request = login_receive(&conn->conn, true);
 854         bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs;
 855         if (bhslr->bhslr_tsih != 0) {
 856                 login_send_error(request, 0x02, 0x0a);
 857                 log_errx(1, "received Login PDU with non-zero TSIH");
 858         }
 859
 860         pg = conn->conn_portal->p_portal_group;
 861
 862         memcpy(conn->conn_initiator_isid, bhslr->bhslr_isid,
 863             sizeof(conn->conn_initiator_isid));
 864
 865         /*
 866          * XXX: Implement the C flag some day.
 867          */
 868         request_keys = keys_new();
 869         keys_load_pdu(request_keys, request);
 870
 871         assert(conn->conn_initiator_name == NULL);
 872         initiator_name = keys_find(request_keys, "InitiatorName");
 873         if (initiator_name == NULL) {
 874                 login_send_error(request, 0x02, 0x07);
 875                 log_errx(1, "received Login PDU without InitiatorName");
 876         }
 877         if (valid_iscsi_name(initiator_name) == false) {
 878                 login_send_error(request, 0x02, 0x00);
 879                 log_errx(1, "received Login PDU with invalid InitiatorName");
 880         }
 881         conn->conn_initiator_name = checked_strdup(initiator_name);
 882         log_set_peer_name(conn->conn_initiator_name);
 883         setproctitle("%s (%s)", conn->conn_initiator_addr, conn->conn_initiator_name);
 884
 885         redirected = login_portal_redirect(conn, request);
 886         if (redirected) {
 887                 log_debugx("initiator redirected; exiting");
 888                 exit(0);
 889         }
 890
 891         initiator_alias = keys_find(request_keys, "InitiatorAlias");
 892         if (initiator_alias != NULL)
 893                 conn->conn_initiator_alias = checked_strdup(initiator_alias);
 894
 895         assert(conn->conn_session_type == CONN_SESSION_TYPE_NONE);
 896         session_type = keys_find(request_keys, "SessionType");
 897         if (session_type != NULL) {
 898                 if (strcmp(session_type, "Normal") == 0) {
 899                         conn->conn_session_type = CONN_SESSION_TYPE_NORMAL;
 900                 } else if (strcmp(session_type, "Discovery") == 0) {
 901                         conn->conn_session_type = CONN_SESSION_TYPE_DISCOVERY;
 902                 } else {
 903                         login_send_error(request, 0x02, 0x00);
 904                         log_errx(1, "received Login PDU with invalid "
 905                             "SessionType \"%s\"", session_type);
 906                 }
 907         } else
 908                 conn->conn_session_type = CONN_SESSION_TYPE_NORMAL;
 909
 910         assert(conn->conn_target == NULL);
 911         if (conn->conn_session_type == CONN_SESSION_TYPE_NORMAL) {
 912                 target_name = keys_find(request_keys, "TargetName");
 913                 if (target_name == NULL) {
 914                         login_send_error(request, 0x02, 0x07);
 915                         log_errx(1, "received Login PDU without TargetName");
 916                 }
 917
 918                 conn->conn_port = port_find_in_pg(pg, target_name);
 919                 if (conn->conn_port == NULL) {
 920                         login_send_error(request, 0x02, 0x03);
 921                         log_errx(1, "requested target \"%s\" not found",
 922                             target_name);
 923                 }
 924                 conn->conn_target = conn->conn_port->p_target;
 925         }
 926
 927         /*
 928          * At this point we know what kind of authentication we need.
 929          */
 930         if (conn->conn_session_type == CONN_SESSION_TYPE_NORMAL) {
 931                 ag = conn->conn_port->p_auth_group;
 932                 if (ag == NULL)
 933                         ag = conn->conn_target->t_auth_group;
 934                 if (ag->ag_name != NULL) {
 935                         log_debugx("initiator requests to connect "
 936                             "to target \"%s\"; auth-group \"%s\"",
 937                             conn->conn_target->t_name,
 938                             ag->ag_name);
 939                 } else {
 940                         log_debugx("initiator requests to connect "
 941                             "to target \"%s\"", conn->conn_target->t_name);
 942                 }
 943         } else {
 944                 assert(conn->conn_session_type == CONN_SESSION_TYPE_DISCOVERY);
 945                 ag = pg->pg_discovery_auth_group;
 946                 if (ag->ag_name != NULL) {
 947                         log_debugx("initiator requests "
 948                             "discovery session; auth-group \"%s\"", ag->ag_name);
 949                 } else {
 950                         log_debugx("initiator requests discovery session");
 951                 }
 952         }
 953
 954         if (ag->ag_type == AG_TYPE_DENY) {
 955                 login_send_error(request, 0x02, 0x01);
 956                 log_errx(1, "auth-type is \"deny\"");
 957         }
 958
 959         if (ag->ag_type == AG_TYPE_UNKNOWN) {
 960                 /*
 961                  * This can happen with empty auth-group.
 962                  */
 963                 login_send_error(request, 0x02, 0x01);
 964                 log_errx(1, "auth-type not set, denying access");
 965         }
 966
 967         /*
 968          * Enforce initiator-name and initiator-portal.
 969          */
 970         if (auth_name_check(ag, initiator_name) != 0) {
 971                 login_send_error(request, 0x02, 0x02);
 972                 log_errx(1, "initiator does not match allowed initiator names");
 973         }
 974
 975         if (auth_portal_check(ag, &conn->conn_initiator_sa) != 0) {
 976                 login_send_error(request, 0x02, 0x02);
 977                 log_errx(1, "initiator does not match allowed "
 978                     "initiator portals");
 979         }
 980
 981         /*
 982          * Let's see if the initiator intends to do any kind of authentication
 983          * at all.
 984          */
 985         if (login_csg(request) == BHSLR_STAGE_OPERATIONAL_NEGOTIATION) {
 986                 if (ag->ag_type != AG_TYPE_NO_AUTHENTICATION) {
 987                         login_send_error(request, 0x02, 0x01);
 988                         log_errx(1, "initiator skipped the authentication, "
 989                             "but authentication is required");
 990                 }
 991
 992                 keys_delete(request_keys);
 993
 994                 log_debugx("initiator skipped the authentication, "
 995                     "and we don't need it; proceeding with negotiation");
 996                 login_negotiate(conn, request);
 997                 return;
 998         }
 999
1000         fail = false;
1001         response = login_new_response(request);
1002         response_keys = keys_new();
1003         trans = (bhslr->bhslr_flags & BHSLR_FLAGS_TRANSIT) != 0;
1004         auth_method = keys_find(request_keys, "AuthMethod");
1005         if (ag->ag_type == AG_TYPE_NO_AUTHENTICATION) {
1006                 log_debugx("authentication not required");
1007                 if (auth_method == NULL ||
1008                     login_list_contains(auth_method, "None")) {
1009                         keys_add(response_keys, "AuthMethod", "None");
1010                 } else {
1011                         log_warnx("initiator requests "
1012                             "AuthMethod \"%s\" instead of \"None\"",
1013                             auth_method);
1014                         keys_add(response_keys, "AuthMethod", "Reject");
1015                 }
1016                 if (trans)
1017                         login_set_nsg(response, BHSLR_STAGE_OPERATIONAL_NEGOTIATION);
1018         } else {
1019                 log_debugx("CHAP authentication required");
1020                 if (auth_method == NULL ||
1021                     login_list_contains(auth_method, "CHAP")) {
1022                         keys_add(response_keys, "AuthMethod", "CHAP");
1023                 } else {
1024                         log_warnx("initiator requests unsupported "
1025                             "AuthMethod \"%s\" instead of \"CHAP\"",
1026                             auth_method);
1027                         keys_add(response_keys, "AuthMethod", "Reject");
1028                         fail = true;
1029                 }
1030         }
1031         if (conn->conn_session_type == CONN_SESSION_TYPE_NORMAL) {
1032                 if (conn->conn_target->t_alias != NULL)
1033                         keys_add(response_keys,
1034                             "TargetAlias", conn->conn_target->t_alias);
1035                 keys_add_int(response_keys,
1036                     "TargetPortalGroupTag", pg->pg_tag);
1037         }
1038         keys_save_pdu(response_keys, response);
1039
1040         pdu_send(response);
1041         pdu_delete(response);
1042         keys_delete(response_keys);
1043         pdu_delete(request);
1044         keys_delete(request_keys);
1045
1046         if (fail) {
1047                 log_debugx("sent reject for AuthMethod; exiting");
1048                 exit(1);
1049         }
1050
1051         if (ag->ag_type != AG_TYPE_NO_AUTHENTICATION) {
1052                 login_chap(conn, ag);
1053                 login_negotiate(conn, NULL);
1054         } else if (trans) {
1055                 login_negotiate(conn, NULL);
1056         } else {
1057                 login_wait_transition(conn);
1058         }
1059 }