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 <stdint.h>
  37 #include <stdio.h>
  38 #include <stdlib.h>
  39 #include <string.h>
  40 #include <unistd.h>
  41 #include <netinet/in.h>
  42
  43 #include "ctld.h"
  44 #include "iscsi_proto.h"
  45
  46 static void login_send_error(struct pdu *request,
  47     char class, char detail);
  48
  49 static void
  50 login_set_nsg(struct pdu *response, int nsg)
  51 {
  52         struct iscsi_bhs_login_response *bhslr;
  53
  54         assert(nsg == BHSLR_STAGE_SECURITY_NEGOTIATION ||
  55             nsg == BHSLR_STAGE_OPERATIONAL_NEGOTIATION ||
  56             nsg == BHSLR_STAGE_FULL_FEATURE_PHASE);
  57
  58         bhslr = (struct iscsi_bhs_login_response *)response->pdu_bhs;
  59
  60         bhslr->bhslr_flags &= 0xFC;
  61         bhslr->bhslr_flags |= nsg;
  62 }
  63
  64 static int
  65 login_csg(const struct pdu *request)
  66 {
  67         struct iscsi_bhs_login_request *bhslr;
  68
  69         bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs;
  70
  71         return ((bhslr->bhslr_flags & 0x0C) >> 2);
  72 }
  73
  74 static void
  75 login_set_csg(struct pdu *response, int csg)
  76 {
  77         struct iscsi_bhs_login_response *bhslr;
  78
  79         assert(csg == BHSLR_STAGE_SECURITY_NEGOTIATION ||
  80             csg == BHSLR_STAGE_OPERATIONAL_NEGOTIATION ||
  81             csg == BHSLR_STAGE_FULL_FEATURE_PHASE);
  82
  83         bhslr = (struct iscsi_bhs_login_response *)response->pdu_bhs;
  84
  85         bhslr->bhslr_flags &= 0xF3;
  86         bhslr->bhslr_flags |= csg << 2;
  87 }
  88
  89 static struct pdu *
  90 login_receive(struct connection *conn, bool initial)
  91 {
  92         struct pdu *request;
  93         struct iscsi_bhs_login_request *bhslr;
  94
  95         request = pdu_new(conn);
  96         pdu_receive(request);
  97         if ((request->pdu_bhs->bhs_opcode & ~ISCSI_BHS_OPCODE_IMMEDIATE) !=
  98             ISCSI_BHS_OPCODE_LOGIN_REQUEST) {
  99                 /*
 100                  * The first PDU in session is special - if we receive any PDU
 101                  * different than login request, we have to drop the connection
 102                  * without sending response ("A target receiving any PDU
 103                  * except a Login request before the Login Phase is started MUST
 104                  * immediately terminate the connection on which the PDU
 105                  * was received.")
 106                  */
 107                 if (initial == false)
 108                         login_send_error(request, 0x02, 0x0b);
 109                 log_errx(1, "protocol error: received invalid opcode 0x%x",
 110                     request->pdu_bhs->bhs_opcode);
 111         }
 112         bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs;
 113         /*
 114          * XXX: Implement the C flag some day.
 115          */
 116         if ((bhslr->bhslr_flags & BHSLR_FLAGS_CONTINUE) != 0) {
 117                 login_send_error(request, 0x03, 0x00);
 118                 log_errx(1, "received Login PDU with unsupported \"C\" flag");
 119         }
 120         if (bhslr->bhslr_version_max != 0x00) {
 121                 login_send_error(request, 0x02, 0x05);
 122                 log_errx(1, "received Login PDU with unsupported "
 123                     "Version-max 0x%x", bhslr->bhslr_version_max);
 124         }
 125         if (bhslr->bhslr_version_min != 0x00) {
 126                 login_send_error(request, 0x02, 0x05);
 127                 log_errx(1, "received Login PDU with unsupported "
 128                     "Version-min 0x%x", bhslr->bhslr_version_min);
 129         }
 130         if (ntohl(bhslr->bhslr_cmdsn) < conn->conn_cmdsn) {
 131                 login_send_error(request, 0x02, 0x05);
 132                 log_errx(1, "received Login PDU with decreasing CmdSN: "
 133                     "was %d, is %d", 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, 0x05);
 139                 log_errx(1, "received Login PDU with wrong ExpStatSN: "
 140                     "is %d, should be %d", 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 iscsi_bhs_login_response *bhslr2;
 343         struct rchap *rchap;
 344         const char *chap_i, *chap_c;
 345         char *chap_r;
 346         int error;
 347
 348         response = login_new_response(request);
 349         bhslr2 = (struct iscsi_bhs_login_response *)response->pdu_bhs;
 350         bhslr2->bhslr_flags |= BHSLR_FLAGS_TRANSIT;
 351         login_set_nsg(response, BHSLR_STAGE_OPERATIONAL_NEGOTIATION);
 352
 353         /*
 354          * Actually, one more thing: mutual authentication.
 355          */
 356         request_keys = keys_new();
 357         keys_load(request_keys, request);
 358         chap_i = keys_find(request_keys, "CHAP_I");
 359         chap_c = keys_find(request_keys, "CHAP_C");
 360         if (chap_i != NULL || chap_c != NULL) {
 361                 if (chap_i == NULL) {
 362                         login_send_error(request, 0x02, 0x07);
 363                         log_errx(1, "initiator requested target "
 364                             "authentication, but didn't send CHAP_I");
 365                 }
 366                 if (chap_c == NULL) {
 367                         login_send_error(request, 0x02, 0x07);
 368                         log_errx(1, "initiator requested target "
 369                             "authentication, but didn't send CHAP_C");
 370                 }
 371                 if (auth->a_auth_group->ag_type != AG_TYPE_CHAP_MUTUAL) {
 372                         login_send_error(request, 0x02, 0x01);
 373                         log_errx(1, "initiator requests target authentication "
 374                             "for user \"%s\", but mutual user/secret "
 375                             "is not set", auth->a_user);
 376                 }
 377
 378                 log_debugx("performing mutual authentication as user \"%s\"",
 379                     auth->a_mutual_user);
 380
 381                 rchap = rchap_new(auth->a_mutual_secret);
 382                 error = rchap_receive(rchap, chap_i, chap_c);
 383                 if (error != 0) {
 384                         login_send_error(request, 0x02, 0x07);
 385                         log_errx(1, "received CHAP Login PDU with malformed "
 386                             "CHAP_I or CHAP_C");
 387                 }
 388                 chap_r = rchap_get_response(rchap);
 389                 rchap_delete(rchap);
 390                 response_keys = keys_new();
 391                 keys_add(response_keys, "CHAP_N", auth->a_mutual_user);
 392                 keys_add(response_keys, "CHAP_R", chap_r);
 393                 free(chap_r);
 394                 keys_save(response_keys, response);
 395                 keys_delete(response_keys);
 396         } else {
 397                 log_debugx("initiator did not request target authentication");
 398         }
 399
 400         keys_delete(request_keys);
 401         pdu_send(response);
 402         pdu_delete(response);
 403 }
 404
 405 static void
 406 login_chap(struct connection *conn, struct auth_group *ag)
 407 {
 408         const struct auth *auth;
 409         struct chap *chap;
 410         struct pdu *request;
 411
 412         /*
 413          * Receive CHAP_A PDU.
 414          */
 415         log_debugx("beginning CHAP authentication; waiting for CHAP_A");
 416         request = login_receive_chap_a(conn);
 417
 418         /*
 419          * Generate the challenge.
 420          */
 421         chap = chap_new();
 422
 423         /*
 424          * Send the challenge.
 425          */
 426         log_debugx("sending CHAP_C, binary challenge size is %zd bytes",
 427             sizeof(chap->chap_challenge));
 428         login_send_chap_c(request, chap);
 429         pdu_delete(request);
 430
 431         /*
 432          * Receive CHAP_N/CHAP_R PDU and authenticate.
 433          */
 434         log_debugx("waiting for CHAP_N/CHAP_R");
 435         request = login_receive_chap_r(conn, ag, chap, &auth);
 436
 437         /*
 438          * Yay, authentication succeeded!
 439          */
 440         log_debugx("authentication succeeded for user \"%s\"; "
 441             "transitioning to Negotiation Phase", auth->a_user);
 442         login_send_chap_success(request, auth);
 443         pdu_delete(request);
 444         chap_delete(chap);
 445 }
 446
 447 static void
 448 login_negotiate_key(struct pdu *request, const char *name,
 449     const char *value, bool skipped_security, struct keys *response_keys)
 450 {
 451         int which, tmp;
 452         struct connection *conn;
 453
 454         conn = request->pdu_connection;
 455
 456         if (strcmp(name, "InitiatorName") == 0) {
 457                 if (!skipped_security)
 458                         log_errx(1, "initiator resent InitiatorName");
 459         } else if (strcmp(name, "SessionType") == 0) {
 460                 if (!skipped_security)
 461                         log_errx(1, "initiator resent SessionType");
 462         } else if (strcmp(name, "TargetName") == 0) {
 463                 if (!skipped_security)
 464                         log_errx(1, "initiator resent TargetName");
 465         } else if (strcmp(name, "InitiatorAlias") == 0) {
 466                 if (conn->conn_initiator_alias != NULL)
 467                         free(conn->conn_initiator_alias);
 468                 conn->conn_initiator_alias = checked_strdup(value);
 469         } else if (strcmp(value, "Irrelevant") == 0) {
 470                 /* Ignore. */
 471         } else if (strcmp(name, "HeaderDigest") == 0) {
 472                 /*
 473                  * We don't handle digests for discovery sessions.
 474                  */
 475                 if (conn->conn_session_type == CONN_SESSION_TYPE_DISCOVERY) {
 476                         log_debugx("discovery session; digests disabled");
 477                         keys_add(response_keys, name, "None");
 478                         return;
 479                 }
 480
 481                 which = login_list_prefers(value, "CRC32C", "None");
 482                 switch (which) {
 483                 case 1:
 484                         log_debugx("initiator prefers CRC32C "
 485                             "for header digest; we'll use it");
 486                         conn->conn_header_digest = CONN_DIGEST_CRC32C;
 487                         keys_add(response_keys, name, "CRC32C");
 488                         break;
 489                 case 2:
 490                         log_debugx("initiator prefers not to do "
 491                             "header digest; we'll comply");
 492                         keys_add(response_keys, name, "None");
 493                         break;
 494                 default:
 495                         log_warnx("initiator sent unrecognized "
 496                             "HeaderDigest value \"%s\"; will use None", value);
 497                         keys_add(response_keys, name, "None");
 498                         break;
 499                 }
 500         } else if (strcmp(name, "DataDigest") == 0) {
 501                 if (conn->conn_session_type == CONN_SESSION_TYPE_DISCOVERY) {
 502                         log_debugx("discovery session; digests disabled");
 503                         keys_add(response_keys, name, "None");
 504                         return;
 505                 }
 506
 507                 which = login_list_prefers(value, "CRC32C", "None");
 508                 switch (which) {
 509                 case 1:
 510                         log_debugx("initiator prefers CRC32C "
 511                             "for data digest; we'll use it");
 512                         conn->conn_data_digest = CONN_DIGEST_CRC32C;
 513                         keys_add(response_keys, name, "CRC32C");
 514                         break;
 515                 case 2:
 516                         log_debugx("initiator prefers not to do "
 517                             "data digest; we'll comply");
 518                         keys_add(response_keys, name, "None");
 519                         break;
 520                 default:
 521                         log_warnx("initiator sent unrecognized "
 522                             "DataDigest value \"%s\"; will use None", value);
 523                         keys_add(response_keys, name, "None");
 524                         break;
 525                 }
 526         } else if (strcmp(name, "MaxConnections") == 0) {
 527                 keys_add(response_keys, name, "1");
 528         } else if (strcmp(name, "InitialR2T") == 0) {
 529                 keys_add(response_keys, name, "Yes");
 530         } else if (strcmp(name, "ImmediateData") == 0) {
 531                 if (conn->conn_session_type == CONN_SESSION_TYPE_DISCOVERY) {
 532                         log_debugx("discovery session; ImmediateData irrelevant");
 533                         keys_add(response_keys, name, "Irrelevant");
 534                 } else {
 535                         if (strcmp(value, "Yes") == 0) {
 536                                 conn->conn_immediate_data = true;
 537                                 keys_add(response_keys, name, "Yes");
 538                         } else {
 539                                 conn->conn_immediate_data = false;
 540                                 keys_add(response_keys, name, "No");
 541                         }
 542                 }
 543         } else if (strcmp(name, "MaxRecvDataSegmentLength") == 0) {
 544                 tmp = strtoul(value, NULL, 10);
 545                 if (tmp <= 0) {
 546                         login_send_error(request, 0x02, 0x00);
 547                         log_errx(1, "received invalid "
 548                             "MaxRecvDataSegmentLength");
 549                 }
 550                 if (tmp > MAX_DATA_SEGMENT_LENGTH) {
 551                         log_debugx("capping MaxRecvDataSegmentLength "
 552                             "from %d to %d", tmp, MAX_DATA_SEGMENT_LENGTH);
 553                         tmp = MAX_DATA_SEGMENT_LENGTH;
 554                 }
 555                 conn->conn_max_data_segment_length = tmp;
 556                 keys_add_int(response_keys, name, tmp);
 557         } else if (strcmp(name, "MaxBurstLength") == 0) {
 558                 tmp = strtoul(value, NULL, 10);
 559                 if (tmp <= 0) {
 560                         login_send_error(request, 0x02, 0x00);
 561                         log_errx(1, "received invalid MaxBurstLength");
 562                 }
 563                 if (tmp > MAX_BURST_LENGTH) {
 564                         log_debugx("capping MaxBurstLength from %d to %d",
 565                             tmp, MAX_BURST_LENGTH);
 566                         tmp = MAX_BURST_LENGTH;
 567                 }
 568                 conn->conn_max_burst_length = tmp;
 569                 keys_add(response_keys, name, value);
 570         } else if (strcmp(name, "FirstBurstLength") == 0) {
 571                 tmp = strtoul(value, NULL, 10);
 572                 if (tmp <= 0) {
 573                         login_send_error(request, 0x02, 0x00);
 574                         log_errx(1, "received invalid "
 575                             "FirstBurstLength");
 576                 }
 577                 if (tmp > MAX_DATA_SEGMENT_LENGTH) {
 578                         log_debugx("capping FirstBurstLength from %d to %d",
 579                             tmp, MAX_DATA_SEGMENT_LENGTH);
 580                         tmp = MAX_DATA_SEGMENT_LENGTH;
 581                 }
 582                 /*
 583                  * We don't pass the value to the kernel; it only enforces
 584                  * hardcoded limit anyway.
 585                  */
 586                 keys_add_int(response_keys, name, tmp);
 587         } else if (strcmp(name, "DefaultTime2Wait") == 0) {
 588                 keys_add(response_keys, name, value);
 589         } else if (strcmp(name, "DefaultTime2Retain") == 0) {
 590                 keys_add(response_keys, name, "0");
 591         } else if (strcmp(name, "MaxOutstandingR2T") == 0) {
 592                 keys_add(response_keys, name, "1");
 593         } else if (strcmp(name, "DataPDUInOrder") == 0) {
 594                 keys_add(response_keys, name, "Yes");
 595         } else if (strcmp(name, "DataSequenceInOrder") == 0) {
 596                 keys_add(response_keys, name, "Yes");
 597         } else if (strcmp(name, "ErrorRecoveryLevel") == 0) {
 598                 keys_add(response_keys, name, "0");
 599         } else if (strcmp(name, "OFMarker") == 0) {
 600                 keys_add(response_keys, name, "No");
 601         } else if (strcmp(name, "IFMarker") == 0) {
 602                 keys_add(response_keys, name, "No");
 603         } else {
 604                 log_debugx("unknown key \"%s\"; responding "
 605                     "with NotUnderstood", name);
 606                 keys_add(response_keys, name, "NotUnderstood");
 607         }
 608 }
 609
 610 static void
 611 login_negotiate(struct connection *conn, struct pdu *request)
 612 {
 613         struct pdu *response;
 614         struct iscsi_bhs_login_response *bhslr2;
 615         struct keys *request_keys, *response_keys;
 616         int i;
 617         bool skipped_security;
 618
 619         if (request == NULL) {
 620                 log_debugx("beginning operational parameter negotiation; "
 621                     "waiting for Login PDU");
 622                 request = login_receive(conn, false);
 623                 skipped_security = false;
 624         } else
 625                 skipped_security = true;
 626
 627         request_keys = keys_new();
 628         keys_load(request_keys, request);
 629
 630         response = login_new_response(request);
 631         bhslr2 = (struct iscsi_bhs_login_response *)response->pdu_bhs;
 632         bhslr2->bhslr_flags |= BHSLR_FLAGS_TRANSIT;
 633         bhslr2->bhslr_tsih = htons(0xbadd);
 634         login_set_csg(response, BHSLR_STAGE_OPERATIONAL_NEGOTIATION);
 635         login_set_nsg(response, BHSLR_STAGE_FULL_FEATURE_PHASE);
 636         response_keys = keys_new();
 637
 638         if (skipped_security &&
 639             conn->conn_session_type == CONN_SESSION_TYPE_NORMAL) {
 640                 if (conn->conn_target->t_alias != NULL)
 641                         keys_add(response_keys,
 642                             "TargetAlias", conn->conn_target->t_alias);
 643                 keys_add_int(response_keys, "TargetPortalGroupTag",
 644                     conn->conn_portal->p_portal_group->pg_tag);
 645         }
 646
 647         for (i = 0; i < KEYS_MAX; i++) {
 648                 if (request_keys->keys_names[i] == NULL)
 649                         break;
 650
 651                 login_negotiate_key(request, request_keys->keys_names[i],
 652                     request_keys->keys_values[i], skipped_security,
 653                     response_keys);
 654         }
 655
 656         log_debugx("operational parameter negotiation done; "
 657             "transitioning to Full Feature Phase");
 658
 659         keys_save(response_keys, response);
 660         pdu_send(response);
 661         pdu_delete(response);
 662         keys_delete(response_keys);
 663         pdu_delete(request);
 664         keys_delete(request_keys);
 665 }
 666
 667 void
 668 login(struct connection *conn)
 669 {
 670         struct pdu *request, *response;
 671         struct iscsi_bhs_login_request *bhslr;
 672         struct iscsi_bhs_login_response *bhslr2;
 673         struct keys *request_keys, *response_keys;
 674         struct auth_group *ag;
 675         const char *initiator_name, *initiator_alias, *session_type,
 676             *target_name, *auth_method;
 677
 678         /*
 679          * Handle the initial Login Request - figure out required authentication
 680          * method and either transition to the next phase, if no authentication
 681          * is required, or call appropriate authentication code.
 682          */
 683         log_debugx("beginning Login Phase; waiting for Login PDU");
 684         request = login_receive(conn, true);
 685         bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs;
 686         if (bhslr->bhslr_tsih != 0) {
 687                 login_send_error(request, 0x02, 0x0a);
 688                 log_errx(1, "received Login PDU with non-zero TSIH");
 689         }
 690
 691         memcpy(conn->conn_initiator_isid, bhslr->bhslr_isid,
 692             sizeof(conn->conn_initiator_isid));
 693
 694         /*
 695          * XXX: Implement the C flag some day.
 696          */
 697         request_keys = keys_new();
 698         keys_load(request_keys, request);
 699
 700         assert(conn->conn_initiator_name == NULL);
 701         initiator_name = keys_find(request_keys, "InitiatorName");
 702         if (initiator_name == NULL) {
 703                 login_send_error(request, 0x02, 0x07);
 704                 log_errx(1, "received Login PDU without InitiatorName");
 705         }
 706         if (valid_iscsi_name(initiator_name) == false) {
 707                 login_send_error(request, 0x02, 0x00);
 708                 log_errx(1, "received Login PDU with invalid InitiatorName");
 709         }
 710         conn->conn_initiator_name = checked_strdup(initiator_name);
 711         log_set_peer_name(conn->conn_initiator_name);
 712         /*
 713          * XXX: This doesn't work (does nothing) because of Capsicum.
 714          */
 715         setproctitle("%s (%s)", conn->conn_initiator_addr, conn->conn_initiator_name);
 716
 717         initiator_alias = keys_find(request_keys, "InitiatorAlias");
 718         if (initiator_alias != NULL)
 719                 conn->conn_initiator_alias = checked_strdup(initiator_alias);
 720
 721         assert(conn->conn_session_type == CONN_SESSION_TYPE_NONE);
 722         session_type = keys_find(request_keys, "SessionType");
 723         if (session_type != NULL) {
 724                 if (strcmp(session_type, "Normal") == 0) {
 725                         conn->conn_session_type = CONN_SESSION_TYPE_NORMAL;
 726                 } else if (strcmp(session_type, "Discovery") == 0) {
 727                         conn->conn_session_type = CONN_SESSION_TYPE_DISCOVERY;
 728                 } else {
 729                         login_send_error(request, 0x02, 0x00);
 730                         log_errx(1, "received Login PDU with invalid "
 731                             "SessionType \"%s\"", session_type);
 732                 }
 733         } else
 734                 conn->conn_session_type = CONN_SESSION_TYPE_NORMAL;
 735
 736         assert(conn->conn_target == NULL);
 737         if (conn->conn_session_type == CONN_SESSION_TYPE_NORMAL) {
 738                 target_name = keys_find(request_keys, "TargetName");
 739                 if (target_name == NULL) {
 740                         login_send_error(request, 0x02, 0x07);
 741                         log_errx(1, "received Login PDU without TargetName");
 742                 }
 743
 744                 conn->conn_target =
 745                     target_find(conn->conn_portal->p_portal_group->pg_conf,
 746                     target_name);
 747                 if (conn->conn_target == NULL) {
 748                         login_send_error(request, 0x02, 0x03);
 749                         log_errx(1, "requested target \"%s\" not found",
 750                             target_name);
 751                 }
 752         }
 753
 754         /*
 755          * At this point we know what kind of authentication we need.
 756          */
 757         if (conn->conn_session_type == CONN_SESSION_TYPE_NORMAL) {
 758                 ag = conn->conn_target->t_auth_group;
 759                 if (ag->ag_name != NULL) {
 760                         log_debugx("initiator requests to connect "
 761                             "to target \"%s\"; auth-group \"%s\"",
 762                             conn->conn_target->t_name,
 763                             conn->conn_target->t_auth_group->ag_name);
 764                 } else {
 765                         log_debugx("initiator requests to connect "
 766                             "to target \"%s\"", conn->conn_target->t_name);
 767                 }
 768         } else {
 769                 assert(conn->conn_session_type == CONN_SESSION_TYPE_DISCOVERY);
 770                 ag = conn->conn_portal->p_portal_group->pg_discovery_auth_group;
 771                 if (ag->ag_name != NULL) {
 772                         log_debugx("initiator requests "
 773                             "discovery session; auth-group \"%s\"", ag->ag_name);
 774                 } else {
 775                         log_debugx("initiator requests discovery session");
 776                 }
 777         }
 778
 779         /*
 780          * Enforce initiator-name and initiator-portal.
 781          */
 782         if (auth_name_defined(ag)) {
 783                 if (auth_name_find(ag, initiator_name) == NULL) {
 784                         login_send_error(request, 0x02, 0x02);
 785                         log_errx(1, "initiator does not match allowed "
 786                             "initiator names");
 787                 }
 788                 log_debugx("initiator matches allowed initiator names");
 789         } else {
 790                 log_debugx("auth-group does not define initiator name "
 791                     "restrictions");
 792         }
 793
 794         if (auth_portal_defined(ag)) {
 795                 if (auth_portal_find(ag, &conn->conn_initiator_sa) == NULL) {
 796                         login_send_error(request, 0x02, 0x02);
 797                         log_errx(1, "initiator does not match allowed "
 798                             "initiator portals");
 799                 }
 800                 log_debugx("initiator matches allowed initiator portals");
 801         } else {
 802                 log_debugx("auth-group does not define initiator portal "
 803                     "restrictions");
 804         }
 805
 806         /*
 807          * Let's see if the initiator intends to do any kind of authentication
 808          * at all.
 809          */
 810         if (login_csg(request) == BHSLR_STAGE_OPERATIONAL_NEGOTIATION) {
 811                 if (ag->ag_type != AG_TYPE_NO_AUTHENTICATION) {
 812                         login_send_error(request, 0x02, 0x01);
 813                         log_errx(1, "initiator skipped the authentication, "
 814                             "but authentication is required");
 815                 }
 816
 817                 keys_delete(request_keys);
 818
 819                 log_debugx("initiator skipped the authentication, "
 820                     "and we don't need it; proceeding with negotiation");
 821                 login_negotiate(conn, request);
 822                 return;
 823         }
 824
 825         if (ag->ag_type == AG_TYPE_NO_AUTHENTICATION) {
 826                 /*
 827                  * Initiator might want to to authenticate,
 828                  * but we don't need it.
 829                  */
 830                 log_debugx("authentication not required; "
 831                     "transitioning to operational parameter negotiation");
 832
 833                 if ((bhslr->bhslr_flags & BHSLR_FLAGS_TRANSIT) == 0)
 834                         log_warnx("initiator did not set the \"T\" flag; "
 835                             "transitioning anyway");
 836
 837                 response = login_new_response(request);
 838                 bhslr2 = (struct iscsi_bhs_login_response *)response->pdu_bhs;
 839                 bhslr2->bhslr_flags |= BHSLR_FLAGS_TRANSIT;
 840                 login_set_nsg(response,
 841                     BHSLR_STAGE_OPERATIONAL_NEGOTIATION);
 842                 response_keys = keys_new();
 843                 /*
 844                  * Required by Linux initiator.
 845                  */
 846                 auth_method = keys_find(request_keys, "AuthMethod");
 847                 if (auth_method != NULL &&
 848                     login_list_contains(auth_method, "None"))
 849                         keys_add(response_keys, "AuthMethod", "None");
 850
 851                 if (conn->conn_session_type == CONN_SESSION_TYPE_NORMAL) {
 852                         if (conn->conn_target->t_alias != NULL)
 853                                 keys_add(response_keys,
 854                                     "TargetAlias", conn->conn_target->t_alias);
 855                         keys_add_int(response_keys, "TargetPortalGroupTag",
 856                             conn->conn_portal->p_portal_group->pg_tag);
 857                 }
 858                 keys_save(response_keys, response);
 859                 pdu_send(response);
 860                 pdu_delete(response);
 861                 keys_delete(response_keys);
 862                 pdu_delete(request);
 863                 keys_delete(request_keys);
 864
 865                 login_negotiate(conn, NULL);
 866                 return;
 867         }
 868
 869         if (ag->ag_type == AG_TYPE_DENY) {
 870                 login_send_error(request, 0x02, 0x01);
 871                 log_errx(1, "auth-type is \"deny\"");
 872         }
 873
 874         if (ag->ag_type == AG_TYPE_UNKNOWN) {
 875                 /*
 876                  * This can happen with empty auth-group.
 877                  */
 878                 login_send_error(request, 0x02, 0x01);
 879                 log_errx(1, "auth-type not set, denying access");
 880         }
 881
 882         log_debugx("CHAP authentication required");
 883
 884         auth_method = keys_find(request_keys, "AuthMethod");
 885         if (auth_method == NULL) {
 886                 login_send_error(request, 0x02, 0x07);
 887                 log_errx(1, "received Login PDU without AuthMethod");
 888         }
 889         /*
 890          * XXX: This should be Reject, not just a login failure (5.3.2).
 891          */
 892         if (login_list_contains(auth_method, "CHAP") == 0) {
 893                 login_send_error(request, 0x02, 0x01);
 894                 log_errx(1, "initiator requests unsupported AuthMethod \"%s\" "
 895                     "instead of \"CHAP\"", auth_method);
 896         }
 897
 898         response = login_new_response(request);
 899
 900         response_keys = keys_new();
 901         keys_add(response_keys, "AuthMethod", "CHAP");
 902         if (conn->conn_session_type == CONN_SESSION_TYPE_NORMAL) {
 903                 if (conn->conn_target->t_alias != NULL)
 904                         keys_add(response_keys,
 905                             "TargetAlias", conn->conn_target->t_alias);
 906                 keys_add_int(response_keys, "TargetPortalGroupTag",
 907                     conn->conn_portal->p_portal_group->pg_tag);
 908         }
 909         keys_save(response_keys, response);
 910
 911         pdu_send(response);
 912         pdu_delete(response);
 913         keys_delete(response_keys);
 914         pdu_delete(request);
 915         keys_delete(request_keys);
 916
 917         login_chap(conn, ag);
 918
 919         login_negotiate(conn, NULL);
 920 }