usr.sbin/iscsid/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 <sys/types.h>
  35 #include <sys/ioctl.h>
  36 #include <assert.h>
  37 #include <stdbool.h>
  38 #include <stdio.h>
  39 #include <stdlib.h>
  40 #include <string.h>
  41 #include <netinet/in.h>
  42
  43 #include "iscsid.h"
  44 #include "iscsi_proto.h"
  45
  46 static int
  47 login_nsg(const struct pdu *response)
  48 {
  49         struct iscsi_bhs_login_response *bhslr;
  50
  51         bhslr = (struct iscsi_bhs_login_response *)response->pdu_bhs;
  52
  53         return (bhslr->bhslr_flags & 0x03);
  54 }
  55
  56 static void
  57 login_set_nsg(struct pdu *request, int nsg)
  58 {
  59         struct iscsi_bhs_login_request *bhslr;
  60
  61         assert(nsg == BHSLR_STAGE_SECURITY_NEGOTIATION ||
  62             nsg == BHSLR_STAGE_OPERATIONAL_NEGOTIATION ||
  63             nsg == BHSLR_STAGE_FULL_FEATURE_PHASE);
  64
  65         bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs;
  66
  67         bhslr->bhslr_flags &= 0xFC;
  68         bhslr->bhslr_flags |= nsg;
  69 }
  70
  71 static void
  72 login_set_csg(struct pdu *request, int csg)
  73 {
  74         struct iscsi_bhs_login_request *bhslr;
  75
  76         assert(csg == BHSLR_STAGE_SECURITY_NEGOTIATION ||
  77             csg == BHSLR_STAGE_OPERATIONAL_NEGOTIATION ||
  78             csg == BHSLR_STAGE_FULL_FEATURE_PHASE);
  79
  80         bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs;
  81
  82         bhslr->bhslr_flags &= 0xF3;
  83         bhslr->bhslr_flags |= csg << 2;
  84 }
  85
  86 static const char *
  87 login_target_error_str(int class, int detail)
  88 {
  89         static char msg[128];
  90
  91         /*
  92          * RFC 3270, 10.13.5.  Status-Class and Status-Detail
  93          */
  94         switch (class) {
  95         case 0x01:
  96                 switch (detail) {
  97                 case 0x01:
  98                         return ("Target moved temporarily");
  99                 case 0x02:
 100                         return ("Target moved permanently");
 101                 default:
 102                         snprintf(msg, sizeof(msg), "unknown redirection; "
 103                             "Status-Class 0x%x, Status-Detail 0x%x",
 104                             class, detail);
 105                         return (msg);
 106                 }
 107         case 0x02:
 108                 switch (detail) {
 109                 case 0x00:
 110                         return ("Initiator error");
 111                 case 0x01:
 112                         return ("Authentication failure");
 113                 case 0x02:
 114                         return ("Authorization failure");
 115                 case 0x03:
 116                         return ("Not found");
 117                 case 0x04:
 118                         return ("Target removed");
 119                 case 0x05:
 120                         return ("Unsupported version");
 121                 case 0x06:
 122                         return ("Too many connections");
 123                 case 0x07:
 124                         return ("Missing parameter");
 125                 case 0x08:
 126                         return ("Can't include in session");
 127                 case 0x09:
 128                         return ("Session type not supported");
 129                 case 0x0a:
 130                         return ("Session does not exist");
 131                 case 0x0b:
 132                         return ("Invalid during login");
 133                 default:
 134                         snprintf(msg, sizeof(msg), "unknown initiator error; "
 135                             "Status-Class 0x%x, Status-Detail 0x%x",
 136                             class, detail);
 137                         return (msg);
 138                 }
 139         case 0x03:
 140                 switch (detail) {
 141                 case 0x00:
 142                         return ("Target error");
 143                 case 0x01:
 144                         return ("Service unavailable");
 145                 case 0x02:
 146                         return ("Out of resources");
 147                 default:
 148                         snprintf(msg, sizeof(msg), "unknown target error; "
 149                             "Status-Class 0x%x, Status-Detail 0x%x",
 150                             class, detail);
 151                         return (msg);
 152                 }
 153         default:
 154                 snprintf(msg, sizeof(msg), "unknown error; "
 155                     "Status-Class 0x%x, Status-Detail 0x%x",
 156                     class, detail);
 157                 return (msg);
 158         }
 159 }
 160
 161 static void
 162 kernel_modify(const struct connection *conn, const char *target_address)
 163 {
 164         struct iscsi_session_modify ism;
 165         int error;
 166
 167         memset(&ism, 0, sizeof(ism));
 168         ism.ism_session_id = conn->conn_session_id;
 169         memcpy(&ism.ism_conf, &conn->conn_conf, sizeof(ism.ism_conf));
 170         strlcpy(ism.ism_conf.isc_target_addr, target_address,
 171             sizeof(ism.ism_conf.isc_target));
 172         error = ioctl(conn->conn_iscsi_fd, ISCSISMODIFY, &ism);
 173         if (error != 0) {
 174                 log_err(1, "failed to redirect to %s: ISCSISMODIFY",
 175                     target_address);
 176         }
 177 }
 178
 179 /*
 180  * XXX: The way it works is suboptimal; what should happen is described
 181  *      in draft-gilligan-iscsi-fault-tolerance-00.  That, however, would
 182  *      be much more complicated: we would need to keep "dependencies"
 183  *      for sessions, so that, in case described in draft and using draft
 184  *      terminology, we would have three sessions: one for discovery,
 185  *      one for initial target portal, and one for redirect portal.
 186  *      This would allow us to "backtrack" on connection failure,
 187  *      as described in draft.
 188  */
 189 static void
 190 login_handle_redirection(struct connection *conn, struct pdu *response)
 191 {
 192         struct iscsi_bhs_login_response *bhslr;
 193         struct keys *response_keys;
 194         const char *target_address;
 195
 196         bhslr = (struct iscsi_bhs_login_response *)response->pdu_bhs;
 197         assert (bhslr->bhslr_status_class == 1);
 198
 199         response_keys = keys_new();
 200         keys_load(response_keys, response);
 201
 202         target_address = keys_find(response_keys, "TargetAddress");
 203         if (target_address == NULL)
 204                 log_errx(1, "received redirection without TargetAddress");
 205         if (target_address[0] == '\0')
 206                 log_errx(1, "received redirection with empty TargetAddress");
 207         if (strlen(target_address) >=
 208             sizeof(conn->conn_conf.isc_target_addr) - 1)
 209                 log_errx(1, "received TargetAddress is too long");
 210
 211         log_debugx("received redirection to \"%s\"", target_address);
 212         kernel_modify(conn, target_address);
 213         keys_delete(response_keys);
 214 }
 215
 216 static struct pdu *
 217 login_receive(struct connection *conn)
 218 {
 219         struct pdu *response;
 220         struct iscsi_bhs_login_response *bhslr;
 221         const char *errorstr;
 222         static bool initial = true;
 223
 224         response = pdu_new(conn);
 225         pdu_receive(response);
 226         if (response->pdu_bhs->bhs_opcode != ISCSI_BHS_OPCODE_LOGIN_RESPONSE) {
 227                 log_errx(1, "protocol error: received invalid opcode 0x%x",
 228                     response->pdu_bhs->bhs_opcode);
 229         }
 230         bhslr = (struct iscsi_bhs_login_response *)response->pdu_bhs;
 231         /*
 232          * XXX: Implement the C flag some day.
 233          */
 234         if ((bhslr->bhslr_flags & BHSLR_FLAGS_CONTINUE) != 0)
 235                 log_errx(1, "received Login PDU with unsupported \"C\" flag");
 236         if (bhslr->bhslr_version_max != 0x00)
 237                 log_errx(1, "received Login PDU with unsupported "
 238                     "Version-max 0x%x", bhslr->bhslr_version_max);
 239         if (bhslr->bhslr_version_active != 0x00)
 240                 log_errx(1, "received Login PDU with unsupported "
 241                     "Version-active 0x%x", bhslr->bhslr_version_active);
 242         if (bhslr->bhslr_status_class == 1) {
 243                 login_handle_redirection(conn, response);
 244                 log_debugx("redirection handled; exiting");
 245                 exit(0);
 246         }
 247         if (bhslr->bhslr_status_class != 0) {
 248                 errorstr = login_target_error_str(bhslr->bhslr_status_class,
 249                     bhslr->bhslr_status_detail);
 250                 fail(conn, errorstr);
 251                 log_errx(1, "target returned error: %s", errorstr);
 252         }
 253         if (initial == false &&
 254             ntohl(bhslr->bhslr_statsn) != conn->conn_statsn + 1) {
 255                 /*
 256                  * It's a warning, not an error, to work around what seems
 257                  * to be bug in NetBSD iSCSI target.
 258                  */
 259                 log_warnx("received Login PDU with wrong StatSN: "
 260                     "is %u, should be %u", ntohl(bhslr->bhslr_statsn),
 261                     conn->conn_statsn + 1);
 262         }
 263         conn->conn_tsih = ntohs(bhslr->bhslr_tsih);
 264         conn->conn_statsn = ntohl(bhslr->bhslr_statsn);
 265
 266         initial = false;
 267
 268         return (response);
 269 }
 270
 271 static struct pdu *
 272 login_new_request(struct connection *conn, int csg)
 273 {
 274         struct pdu *request;
 275         struct iscsi_bhs_login_request *bhslr;
 276         int nsg;
 277
 278         request = pdu_new(conn);
 279         bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs;
 280         bhslr->bhslr_opcode = ISCSI_BHS_OPCODE_LOGIN_REQUEST |
 281             ISCSI_BHS_OPCODE_IMMEDIATE;
 282
 283         bhslr->bhslr_flags = BHSLR_FLAGS_TRANSIT;
 284         switch (csg) {
 285         case BHSLR_STAGE_SECURITY_NEGOTIATION:
 286                 nsg = BHSLR_STAGE_OPERATIONAL_NEGOTIATION;
 287                 break;
 288         case BHSLR_STAGE_OPERATIONAL_NEGOTIATION:
 289                 nsg = BHSLR_STAGE_FULL_FEATURE_PHASE;
 290                 break;
 291         default:
 292                 assert(!"invalid csg");
 293                 log_errx(1, "invalid csg %d", csg);
 294         }
 295         login_set_csg(request, csg);
 296         login_set_nsg(request, nsg);
 297
 298         memcpy(bhslr->bhslr_isid, &conn->conn_isid, sizeof(bhslr->bhslr_isid));
 299         bhslr->bhslr_tsih = htons(conn->conn_tsih);
 300         bhslr->bhslr_initiator_task_tag = 0;
 301         bhslr->bhslr_cmdsn = 0;
 302         bhslr->bhslr_expstatsn = htonl(conn->conn_statsn + 1);
 303
 304         return (request);
 305 }
 306
 307 static int
 308 login_list_prefers(const char *list,
 309     const char *choice1, const char *choice2)
 310 {
 311         char *tofree, *str, *token;
 312
 313         tofree = str = checked_strdup(list);
 314
 315         while ((token = strsep(&str, ",")) != NULL) {
 316                 if (strcmp(token, choice1) == 0) {
 317                         free(tofree);
 318                         return (1);
 319                 }
 320                 if (strcmp(token, choice2) == 0) {
 321                         free(tofree);
 322                         return (2);
 323                 }
 324         }
 325         free(tofree);
 326         return (-1);
 327 }
 328
 329 static void
 330 login_negotiate_key(struct connection *conn, const char *name,
 331     const char *value)
 332 {
 333         int which, tmp;
 334
 335         if (strcmp(name, "TargetAlias") == 0) {
 336                 strlcpy(conn->conn_target_alias, value,
 337                     sizeof(conn->conn_target_alias));
 338         } else if (strcmp(value, "Irrelevant") == 0) {
 339                 /* Ignore. */
 340         } else if (strcmp(name, "HeaderDigest") == 0) {
 341                 which = login_list_prefers(value, "CRC32C", "None");
 342                 switch (which) {
 343                 case 1:
 344                         log_debugx("target prefers CRC32C "
 345                             "for header digest; we'll use it");
 346                         conn->conn_header_digest = CONN_DIGEST_CRC32C;
 347                         break;
 348                 case 2:
 349                         log_debugx("target prefers not to do "
 350                             "header digest; we'll comply");
 351                         break;
 352                 default:
 353                         log_warnx("target sent unrecognized "
 354                             "HeaderDigest value \"%s\"; will use None", value);
 355                         break;
 356                 }
 357         } else if (strcmp(name, "DataDigest") == 0) {
 358                 which = login_list_prefers(value, "CRC32C", "None");
 359                 switch (which) {
 360                 case 1:
 361                         log_debugx("target prefers CRC32C "
 362                             "for data digest; we'll use it");
 363                         conn->conn_data_digest = CONN_DIGEST_CRC32C;
 364                         break;
 365                 case 2:
 366                         log_debugx("target prefers not to do "
 367                             "data digest; we'll comply");
 368                         break;
 369                 default:
 370                         log_warnx("target sent unrecognized "
 371                             "DataDigest value \"%s\"; will use None", value);
 372                         break;
 373                 }
 374         } else if (strcmp(name, "MaxConnections") == 0) {
 375                 /* Ignore. */
 376         } else if (strcmp(name, "InitialR2T") == 0) {
 377                 if (strcmp(value, "Yes") == 0)
 378                         conn->conn_initial_r2t = true;
 379                 else
 380                         conn->conn_initial_r2t = false;
 381         } else if (strcmp(name, "ImmediateData") == 0) {
 382                 if (strcmp(value, "Yes") == 0)
 383                         conn->conn_immediate_data = true;
 384                 else
 385                         conn->conn_immediate_data = false;
 386         } else if (strcmp(name, "MaxRecvDataSegmentLength") == 0) {
 387                 tmp = strtoul(value, NULL, 10);
 388                 if (tmp <= 0)
 389                         log_errx(1, "received invalid "
 390                             "MaxRecvDataSegmentLength");
 391                 if (tmp > ISCSI_MAX_DATA_SEGMENT_LENGTH) {
 392                         log_debugx("capping MaxRecvDataSegmentLength "
 393                             "from %d to %d", tmp, ISCSI_MAX_DATA_SEGMENT_LENGTH);
 394                         tmp = ISCSI_MAX_DATA_SEGMENT_LENGTH;
 395                 }
 396                 conn->conn_max_data_segment_length = tmp;
 397         } else if (strcmp(name, "MaxBurstLength") == 0) {
 398                 if (conn->conn_immediate_data) {
 399                         tmp = strtoul(value, NULL, 10);
 400                         if (tmp <= 0)
 401                                 log_errx(1, "received invalid MaxBurstLength");
 402                         conn->conn_max_burst_length = tmp;
 403                 }
 404         } else if (strcmp(name, "FirstBurstLength") == 0) {
 405                 tmp = strtoul(value, NULL, 10);
 406                 if (tmp <= 0)
 407                         log_errx(1, "received invalid FirstBurstLength");
 408                 conn->conn_first_burst_length = tmp;
 409         } else if (strcmp(name, "DefaultTime2Wait") == 0) {
 410                 /* Ignore */
 411         } else if (strcmp(name, "DefaultTime2Retain") == 0) {
 412                 /* Ignore */
 413         } else if (strcmp(name, "MaxOutstandingR2T") == 0) {
 414                 /* Ignore */
 415         } else if (strcmp(name, "DataPDUInOrder") == 0) {
 416                 /* Ignore */
 417         } else if (strcmp(name, "DataSequenceInOrder") == 0) {
 418                 /* Ignore */
 419         } else if (strcmp(name, "ErrorRecoveryLevel") == 0) {
 420                 /* Ignore */
 421         } else if (strcmp(name, "OFMarker") == 0) {
 422                 /* Ignore */
 423         } else if (strcmp(name, "IFMarker") == 0) {
 424                 /* Ignore */
 425         } else if (strcmp(name, "TargetPortalGroupTag") == 0) {
 426                 /* Ignore */
 427         } else {
 428                 log_debugx("unknown key \"%s\"; ignoring",  name);
 429         }
 430 }
 431
 432 static void
 433 login_negotiate(struct connection *conn)
 434 {
 435         struct pdu *request, *response;
 436         struct keys *request_keys, *response_keys;
 437         struct iscsi_bhs_login_response *bhslr;
 438         int i, nrequests = 0;
 439
 440         log_debugx("beginning operational parameter negotiation");
 441         request = login_new_request(conn, BHSLR_STAGE_OPERATIONAL_NEGOTIATION);
 442         request_keys = keys_new();
 443
 444         /*
 445          * The following keys are irrelevant for discovery sessions.
 446          */
 447         if (conn->conn_conf.isc_discovery == 0) {
 448                 if (conn->conn_conf.isc_header_digest != 0)
 449                         keys_add(request_keys, "HeaderDigest", "CRC32C");
 450                 else
 451                         keys_add(request_keys, "HeaderDigest", "None");
 452                 if (conn->conn_conf.isc_data_digest != 0)
 453                         keys_add(request_keys, "DataDigest", "CRC32C");
 454                 else
 455                         keys_add(request_keys, "DataDigest", "None");
 456
 457                 keys_add(request_keys, "ImmediateData", "Yes");
 458                 keys_add_int(request_keys, "MaxBurstLength",
 459                     2 * ISCSI_MAX_DATA_SEGMENT_LENGTH);
 460                 keys_add_int(request_keys, "FirstBurstLength",
 461                     ISCSI_MAX_DATA_SEGMENT_LENGTH);
 462                 keys_add(request_keys, "InitialR2T", "Yes");
 463                 keys_add(request_keys, "MaxOutstandingR2T", "1");
 464         } else {
 465                 keys_add(request_keys, "HeaderDigest", "None");
 466                 keys_add(request_keys, "DataDigest", "None");
 467         }
 468
 469         keys_add_int(request_keys, "MaxRecvDataSegmentLength",
 470             ISCSI_MAX_DATA_SEGMENT_LENGTH);
 471         keys_add(request_keys, "DefaultTime2Wait", "0");
 472         keys_add(request_keys, "DefaultTime2Retain", "0");
 473         keys_add(request_keys, "ErrorRecoveryLevel", "0");
 474         keys_save(request_keys, request);
 475         keys_delete(request_keys);
 476         request_keys = NULL;
 477         pdu_send(request);
 478         pdu_delete(request);
 479         request = NULL;
 480
 481         response = login_receive(conn);
 482         response_keys = keys_new();
 483         keys_load(response_keys, response);
 484         for (i = 0; i < KEYS_MAX; i++) {
 485                 if (response_keys->keys_names[i] == NULL)
 486                         break;
 487
 488                 login_negotiate_key(conn,
 489                     response_keys->keys_names[i], response_keys->keys_values[i]);
 490         }
 491
 492         keys_delete(response_keys);
 493         response_keys = NULL;
 494
 495         for (;;) {
 496                 bhslr = (struct iscsi_bhs_login_response *)response->pdu_bhs;
 497                 if ((bhslr->bhslr_flags & BHSLR_FLAGS_TRANSIT) != 0)
 498                         break;
 499
 500                 nrequests++;
 501                 if (nrequests > 5) {
 502                         log_warnx("received login response "
 503                             "without the \"T\" flag too many times; giving up");
 504                         break;
 505                 }
 506
 507                 log_debugx("received login response "
 508                     "without the \"T\" flag; sending another request");
 509
 510                 pdu_delete(response);
 511
 512                 request = login_new_request(conn,
 513                     BHSLR_STAGE_OPERATIONAL_NEGOTIATION);
 514                 pdu_send(request);
 515                 pdu_delete(request);
 516
 517                 response = login_receive(conn);
 518         }
 519
 520         if (login_nsg(response) != BHSLR_STAGE_FULL_FEATURE_PHASE)
 521                 log_warnx("received final login response with wrong NSG 0x%x",
 522                     login_nsg(response));
 523         pdu_delete(response);
 524
 525         log_debugx("operational parameter negotiation done; "
 526             "transitioning to Full Feature phase");
 527 }
 528
 529 static void
 530 login_send_chap_a(struct connection *conn)
 531 {
 532         struct pdu *request;
 533         struct keys *request_keys;
 534
 535         request = login_new_request(conn, BHSLR_STAGE_SECURITY_NEGOTIATION);
 536         request_keys = keys_new();
 537         keys_add(request_keys, "CHAP_A", "5");
 538         keys_save(request_keys, request);
 539         keys_delete(request_keys);
 540         pdu_send(request);
 541         pdu_delete(request);
 542 }
 543
 544 static void
 545 login_send_chap_r(struct pdu *response)
 546 {
 547         struct connection *conn;
 548         struct pdu *request;
 549         struct keys *request_keys, *response_keys;
 550         struct rchap *rchap;
 551         const char *chap_a, *chap_c, *chap_i;
 552         char *chap_r;
 553         int error;
 554         char *mutual_chap_c, *mutual_chap_i;
 555
 556         /*
 557          * As in the rest of the initiator, 'request' means
 558          * 'initiator -> target', and 'response' means 'target -> initiator',
 559          *
 560          * So, here the 'response' from the target is the packet that contains
 561          * CHAP challenge; our CHAP response goes into 'request'.
 562          */
 563
 564         conn = response->pdu_connection;
 565
 566         response_keys = keys_new();
 567         keys_load(response_keys, response);
 568
 569         /*
 570          * First, compute the response.
 571          */
 572         chap_a = keys_find(response_keys, "CHAP_A");
 573         if (chap_a == NULL)
 574                 log_errx(1, "received CHAP packet without CHAP_A");
 575         chap_c = keys_find(response_keys, "CHAP_C");
 576         if (chap_c == NULL)
 577                 log_errx(1, "received CHAP packet without CHAP_C");
 578         chap_i = keys_find(response_keys, "CHAP_I");
 579         if (chap_i == NULL)
 580                 log_errx(1, "received CHAP packet without CHAP_I");
 581
 582         if (strcmp(chap_a, "5") != 0) {
 583                 log_errx(1, "received CHAP packet "
 584                     "with unsupported CHAP_A \"%s\"", chap_a);
 585         }
 586
 587         rchap = rchap_new(conn->conn_conf.isc_secret);
 588         error = rchap_receive(rchap, chap_i, chap_c);
 589         if (error != 0) {
 590                 log_errx(1, "received CHAP packet "
 591                     "with malformed CHAP_I or CHAP_C");
 592         }
 593         chap_r = rchap_get_response(rchap);
 594         rchap_delete(rchap);
 595
 596         keys_delete(response_keys);
 597
 598         request = login_new_request(conn, BHSLR_STAGE_SECURITY_NEGOTIATION);
 599         request_keys = keys_new();
 600         keys_add(request_keys, "CHAP_N", conn->conn_conf.isc_user);
 601         keys_add(request_keys, "CHAP_R", chap_r);
 602         free(chap_r);
 603
 604         /*
 605          * If we want mutual authentication, we're expected to send
 606          * our CHAP_I/CHAP_C now.
 607          */
 608         if (conn->conn_conf.isc_mutual_user[0] != '\0') {
 609                 log_debugx("requesting mutual authentication; "
 610                     "binary challenge size is %zd bytes",
 611                     sizeof(conn->conn_mutual_chap->chap_challenge));
 612
 613                 assert(conn->conn_mutual_chap == NULL);
 614                 conn->conn_mutual_chap = chap_new();
 615                 mutual_chap_i = chap_get_id(conn->conn_mutual_chap);
 616                 mutual_chap_c = chap_get_challenge(conn->conn_mutual_chap);
 617                 keys_add(request_keys, "CHAP_I", mutual_chap_i);
 618                 keys_add(request_keys, "CHAP_C", mutual_chap_c);
 619                 free(mutual_chap_i);
 620                 free(mutual_chap_c);
 621         }
 622
 623         keys_save(request_keys, request);
 624         keys_delete(request_keys);
 625         pdu_send(request);
 626         pdu_delete(request);
 627 }
 628
 629 static void
 630 login_verify_mutual(const struct pdu *response)
 631 {
 632         struct connection *conn;
 633         struct keys *response_keys;
 634         const char *chap_n, *chap_r;
 635         int error;
 636
 637         conn = response->pdu_connection;
 638
 639         response_keys = keys_new();
 640         keys_load(response_keys, response);
 641
 642         chap_n = keys_find(response_keys, "CHAP_N");
 643         if (chap_n == NULL)
 644                 log_errx(1, "received CHAP Response PDU without CHAP_N");
 645         chap_r = keys_find(response_keys, "CHAP_R");
 646         if (chap_r == NULL)
 647                 log_errx(1, "received CHAP Response PDU without CHAP_R");
 648
 649         error = chap_receive(conn->conn_mutual_chap, chap_r);
 650         if (error != 0)
 651                 log_errx(1, "received CHAP Response PDU with invalid CHAP_R");
 652
 653         if (strcmp(chap_n, conn->conn_conf.isc_mutual_user) != 0) {
 654                 fail(conn, "Mutual CHAP failed");
 655                 log_errx(1, "mutual CHAP authentication failed: wrong user");
 656         }
 657
 658         error = chap_authenticate(conn->conn_mutual_chap,
 659             conn->conn_conf.isc_mutual_secret);
 660         if (error != 0) {
 661                 fail(conn, "Mutual CHAP failed");
 662                 log_errx(1, "mutual CHAP authentication failed: wrong secret");
 663         }
 664
 665         keys_delete(response_keys);
 666         chap_delete(conn->conn_mutual_chap);
 667         conn->conn_mutual_chap = NULL;
 668
 669         log_debugx("mutual CHAP authentication succeeded");
 670 }
 671
 672 static void
 673 login_chap(struct connection *conn)
 674 {
 675         struct pdu *response;
 676
 677         log_debugx("beginning CHAP authentication; sending CHAP_A");
 678         login_send_chap_a(conn);
 679
 680         log_debugx("waiting for CHAP_A/CHAP_C/CHAP_I");
 681         response = login_receive(conn);
 682
 683         log_debugx("sending CHAP_N/CHAP_R");
 684         login_send_chap_r(response);
 685         pdu_delete(response);
 686
 687         /*
 688          * XXX: Make sure this is not susceptible to MITM.
 689          */
 690
 691         log_debugx("waiting for CHAP result");
 692         response = login_receive(conn);
 693         if (conn->conn_conf.isc_mutual_user[0] != '\0')
 694                 login_verify_mutual(response);
 695         pdu_delete(response);
 696
 697         log_debugx("CHAP authentication done");
 698 }
 699
 700 void
 701 login(struct connection *conn)
 702 {
 703         struct pdu *request, *response;
 704         struct keys *request_keys, *response_keys;
 705         struct iscsi_bhs_login_response *bhslr2;
 706         const char *auth_method;
 707         int i;
 708
 709         log_debugx("beginning Login phase; sending Login PDU");
 710         request = login_new_request(conn, BHSLR_STAGE_SECURITY_NEGOTIATION);
 711         request_keys = keys_new();
 712         if (conn->conn_conf.isc_mutual_user[0] != '\0') {
 713                 keys_add(request_keys, "AuthMethod", "CHAP");
 714         } else if (conn->conn_conf.isc_user[0] != '\0') {
 715                 /*
 716                  * Give target a chance to skip authentication if it
 717                  * doesn't feel like it.
 718                  *
 719                  * None is first, CHAP second; this is to work around
 720                  * what seems to be LIO (Linux target) bug: otherwise,
 721                  * if target is configured with no authentication,
 722                  * and we are configured to authenticate, the target
 723                  * will erroneously respond with AuthMethod=CHAP
 724                  * instead of AuthMethod=None, and will subsequently
 725                  * fail the connection.  This usually happens with
 726                  * Discovery sessions, which default to no authentication.
 727                  */
 728                 keys_add(request_keys, "AuthMethod", "None,CHAP");
 729         } else {
 730                 keys_add(request_keys, "AuthMethod", "None");
 731         }
 732         keys_add(request_keys, "InitiatorName",
 733             conn->conn_conf.isc_initiator);
 734         if (conn->conn_conf.isc_initiator_alias[0] != '\0') {
 735                 keys_add(request_keys, "InitiatorAlias",
 736                     conn->conn_conf.isc_initiator_alias);
 737         }
 738         if (conn->conn_conf.isc_discovery == 0) {
 739                 keys_add(request_keys, "SessionType", "Normal");
 740                 keys_add(request_keys,
 741                     "TargetName", conn->conn_conf.isc_target);
 742         } else {
 743                 keys_add(request_keys, "SessionType", "Discovery");
 744         }
 745         keys_save(request_keys, request);
 746         keys_delete(request_keys);
 747         pdu_send(request);
 748         pdu_delete(request);
 749
 750         response = login_receive(conn);
 751
 752         response_keys = keys_new();
 753         keys_load(response_keys, response);
 754
 755         for (i = 0; i < KEYS_MAX; i++) {
 756                 if (response_keys->keys_names[i] == NULL)
 757                         break;
 758
 759                 /*
 760                  * Not interested in AuthMethod at this point; we only need
 761                  * to parse things such as TargetAlias.
 762                  *
 763                  * XXX: This is somewhat ugly.  We should have a way to apply
 764                  *      all the keys to the session and use that by default
 765                  *      instead of discarding them.
 766                  */
 767                 if (strcmp(response_keys->keys_names[i], "AuthMethod") == 0)
 768                         continue;
 769
 770                 login_negotiate_key(conn,
 771                     response_keys->keys_names[i], response_keys->keys_values[i]);
 772         }
 773
 774         bhslr2 = (struct iscsi_bhs_login_response *)response->pdu_bhs;
 775         if ((bhslr2->bhslr_flags & BHSLR_FLAGS_TRANSIT) != 0 &&
 776             login_nsg(response) == BHSLR_STAGE_OPERATIONAL_NEGOTIATION) {
 777                 if (conn->conn_conf.isc_mutual_user[0] != '\0') {
 778                         log_errx(1, "target requested transition "
 779                             "to operational parameter negotiation, "
 780                             "but we require mutual CHAP");
 781                 }
 782
 783                 log_debugx("target requested transition "
 784                     "to operational parameter negotiation");
 785                 keys_delete(response_keys);
 786                 pdu_delete(response);
 787                 login_negotiate(conn);
 788                 return;
 789         }
 790
 791         auth_method = keys_find(response_keys, "AuthMethod");
 792         if (auth_method == NULL)
 793                 log_errx(1, "received response without AuthMethod");
 794         if (strcmp(auth_method, "None") == 0) {
 795                 if (conn->conn_conf.isc_mutual_user[0] != '\0') {
 796                         log_errx(1, "target does not require authantication, "
 797                             "but we require mutual CHAP");
 798                 }
 799
 800                 log_debugx("target does not require authentication");
 801                 keys_delete(response_keys);
 802                 pdu_delete(response);
 803                 login_negotiate(conn);
 804                 return;
 805         }
 806
 807         if (strcmp(auth_method, "CHAP") != 0) {
 808                 fail(conn, "Unsupported AuthMethod");
 809                 log_errx(1, "received response "
 810                     "with unsupported AuthMethod \"%s\"", auth_method);
 811         }
 812
 813         if (conn->conn_conf.isc_user[0] == '\0' ||
 814             conn->conn_conf.isc_secret[0] == '\0') {
 815                 fail(conn, "Authentication required");
 816                 log_errx(1, "target requests CHAP authentication, but we don't "
 817                     "have user and secret");
 818         }
 819
 820         keys_delete(response_keys);
 821         response_keys = NULL;
 822         pdu_delete(response);
 823         response = NULL;
 824
 825         login_chap(conn);
 826         login_negotiate(conn);
 827 }