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                 tmp = strtoul(value, NULL, 10);
 399                 if (tmp <= 0)
 400                         log_errx(1, "received invalid MaxBurstLength");
 401                 if (tmp > MAX_BURST_LENGTH) {
 402                         log_debugx("capping MaxBurstLength "
 403                             "from %d to %d", tmp, MAX_BURST_LENGTH);
 404                         tmp = MAX_BURST_LENGTH;
 405                 }
 406                 conn->conn_max_burst_length = tmp;
 407         } else if (strcmp(name, "FirstBurstLength") == 0) {
 408                 tmp = strtoul(value, NULL, 10);
 409                 if (tmp <= 0)
 410                         log_errx(1, "received invalid FirstBurstLength");
 411                 if (tmp > FIRST_BURST_LENGTH) {
 412                         log_debugx("capping FirstBurstLength "
 413                             "from %d to %d", tmp, FIRST_BURST_LENGTH);
 414                         tmp = FIRST_BURST_LENGTH;
 415                 }
 416                 conn->conn_first_burst_length = tmp;
 417         } else if (strcmp(name, "DefaultTime2Wait") == 0) {
 418                 /* Ignore */
 419         } else if (strcmp(name, "DefaultTime2Retain") == 0) {
 420                 /* Ignore */
 421         } else if (strcmp(name, "MaxOutstandingR2T") == 0) {
 422                 /* Ignore */
 423         } else if (strcmp(name, "DataPDUInOrder") == 0) {
 424                 /* Ignore */
 425         } else if (strcmp(name, "DataSequenceInOrder") == 0) {
 426                 /* Ignore */
 427         } else if (strcmp(name, "ErrorRecoveryLevel") == 0) {
 428                 /* Ignore */
 429         } else if (strcmp(name, "OFMarker") == 0) {
 430                 /* Ignore */
 431         } else if (strcmp(name, "IFMarker") == 0) {
 432                 /* Ignore */
 433         } else if (strcmp(name, "RDMAExtensions") == 0) {
 434                 if (conn->conn_conf.isc_iser == 1 &&
 435                     strcmp(value, "Yes") != 0) {
 436                         log_errx(1, "received unsupported RDMAExtensions");
 437                 }
 438         } else if (strcmp(name, "InitiatorRecvDataSegmentLength") == 0) {
 439                 tmp = strtoul(value, NULL, 10);
 440                 if (tmp <= 0)
 441                         log_errx(1, "received invalid "
 442                             "InitiatorRecvDataSegmentLength");
 443                 if ((size_t)tmp > conn->conn_limits.isl_max_data_segment_length) {
 444                         log_debugx("capping InitiatorRecvDataSegmentLength "
 445                             "from %d to %zd", tmp,
 446                             conn->conn_limits.isl_max_data_segment_length);
 447                         tmp = conn->conn_limits.isl_max_data_segment_length;
 448                 }
 449                 conn->conn_max_data_segment_length = tmp;
 450         } else if (strcmp(name, "TargetPortalGroupTag") == 0) {
 451                 /* Ignore */
 452         } else if (strcmp(name, "TargetRecvDataSegmentLength") == 0) {
 453                 tmp = strtoul(value, NULL, 10);
 454                 if (tmp <= 0) {
 455                         log_errx(1,
 456                             "received invalid TargetRecvDataSegmentLength");
 457                 }
 458                 if ((size_t)tmp > conn->conn_limits.isl_max_data_segment_length) {
 459                         log_debugx("capping TargetRecvDataSegmentLength "
 460                             "from %d to %zd", tmp,
 461                             conn->conn_limits.isl_max_data_segment_length);
 462                         tmp = conn->conn_limits.isl_max_data_segment_length;
 463                 }
 464                 conn->conn_max_data_segment_length = tmp;
 465         } else {
 466                 log_debugx("unknown key \"%s\"; ignoring",  name);
 467         }
 468 }
 469
 470 static void
 471 login_negotiate(struct connection *conn)
 472 {
 473         struct pdu *request, *response;
 474         struct keys *request_keys, *response_keys;
 475         struct iscsi_bhs_login_response *bhslr;
 476         int i, nrequests = 0;
 477
 478         log_debugx("beginning operational parameter negotiation");
 479         request = login_new_request(conn, BHSLR_STAGE_OPERATIONAL_NEGOTIATION);
 480         request_keys = keys_new();
 481
 482         log_debugx("offload \"%s\" limits MaxRecvDataSegmentLength to %zd",
 483             conn->conn_conf.isc_offload,
 484             conn->conn_limits.isl_max_data_segment_length);
 485
 486         /*
 487          * The following keys are irrelevant for discovery sessions.
 488          */
 489         if (conn->conn_conf.isc_discovery == 0) {
 490                 if (conn->conn_conf.isc_header_digest != 0)
 491                         keys_add(request_keys, "HeaderDigest", "CRC32C");
 492                 else
 493                         keys_add(request_keys, "HeaderDigest", "None");
 494                 if (conn->conn_conf.isc_data_digest != 0)
 495                         keys_add(request_keys, "DataDigest", "CRC32C");
 496                 else
 497                         keys_add(request_keys, "DataDigest", "None");
 498
 499                 keys_add(request_keys, "ImmediateData", "Yes");
 500                 keys_add_int(request_keys, "MaxBurstLength", MAX_BURST_LENGTH);
 501                 keys_add_int(request_keys, "FirstBurstLength", FIRST_BURST_LENGTH);
 502                 keys_add(request_keys, "InitialR2T", "Yes");
 503                 keys_add(request_keys, "MaxOutstandingR2T", "1");
 504                 if (conn->conn_conf.isc_iser == 1) {
 505                         keys_add_int(request_keys, "InitiatorRecvDataSegmentLength",
 506                             conn->conn_limits.isl_max_data_segment_length);
 507                         keys_add_int(request_keys, "TargetRecvDataSegmentLength",
 508                             conn->conn_limits.isl_max_data_segment_length);
 509                         keys_add(request_keys, "RDMAExtensions", "Yes");
 510                 } else {
 511                         keys_add_int(request_keys, "MaxRecvDataSegmentLength",
 512                             conn->conn_limits.isl_max_data_segment_length);
 513                 }
 514         } else {
 515                 keys_add(request_keys, "HeaderDigest", "None");
 516                 keys_add(request_keys, "DataDigest", "None");
 517                 keys_add_int(request_keys, "MaxRecvDataSegmentLength",
 518                     conn->conn_limits.isl_max_data_segment_length);
 519         }
 520
 521         keys_add(request_keys, "DefaultTime2Wait", "0");
 522         keys_add(request_keys, "DefaultTime2Retain", "0");
 523         keys_add(request_keys, "ErrorRecoveryLevel", "0");
 524         keys_save(request_keys, request);
 525         keys_delete(request_keys);
 526         request_keys = NULL;
 527         pdu_send(request);
 528         pdu_delete(request);
 529         request = NULL;
 530
 531         response = login_receive(conn);
 532         response_keys = keys_new();
 533         keys_load(response_keys, response);
 534         for (i = 0; i < KEYS_MAX; i++) {
 535                 if (response_keys->keys_names[i] == NULL)
 536                         break;
 537
 538                 login_negotiate_key(conn,
 539                     response_keys->keys_names[i], response_keys->keys_values[i]);
 540         }
 541
 542         keys_delete(response_keys);
 543         response_keys = NULL;
 544
 545         for (;;) {
 546                 bhslr = (struct iscsi_bhs_login_response *)response->pdu_bhs;
 547                 if ((bhslr->bhslr_flags & BHSLR_FLAGS_TRANSIT) != 0)
 548                         break;
 549
 550                 nrequests++;
 551                 if (nrequests > 5) {
 552                         log_warnx("received login response "
 553                             "without the \"T\" flag too many times; giving up");
 554                         break;
 555                 }
 556
 557                 log_debugx("received login response "
 558                     "without the \"T\" flag; sending another request");
 559
 560                 pdu_delete(response);
 561
 562                 request = login_new_request(conn,
 563                     BHSLR_STAGE_OPERATIONAL_NEGOTIATION);
 564                 pdu_send(request);
 565                 pdu_delete(request);
 566
 567                 response = login_receive(conn);
 568         }
 569
 570         if (login_nsg(response) != BHSLR_STAGE_FULL_FEATURE_PHASE)
 571                 log_warnx("received final login response with wrong NSG 0x%x",
 572                     login_nsg(response));
 573         pdu_delete(response);
 574
 575         log_debugx("operational parameter negotiation done; "
 576             "transitioning to Full Feature phase");
 577 }
 578
 579 static void
 580 login_send_chap_a(struct connection *conn)
 581 {
 582         struct pdu *request;
 583         struct keys *request_keys;
 584
 585         request = login_new_request(conn, BHSLR_STAGE_SECURITY_NEGOTIATION);
 586         request_keys = keys_new();
 587         keys_add(request_keys, "CHAP_A", "5");
 588         keys_save(request_keys, request);
 589         keys_delete(request_keys);
 590         pdu_send(request);
 591         pdu_delete(request);
 592 }
 593
 594 static void
 595 login_send_chap_r(struct pdu *response)
 596 {
 597         struct connection *conn;
 598         struct pdu *request;
 599         struct keys *request_keys, *response_keys;
 600         struct rchap *rchap;
 601         const char *chap_a, *chap_c, *chap_i;
 602         char *chap_r;
 603         int error;
 604         char *mutual_chap_c, *mutual_chap_i;
 605
 606         /*
 607          * As in the rest of the initiator, 'request' means
 608          * 'initiator -> target', and 'response' means 'target -> initiator',
 609          *
 610          * So, here the 'response' from the target is the packet that contains
 611          * CHAP challenge; our CHAP response goes into 'request'.
 612          */
 613
 614         conn = response->pdu_connection;
 615
 616         response_keys = keys_new();
 617         keys_load(response_keys, response);
 618
 619         /*
 620          * First, compute the response.
 621          */
 622         chap_a = keys_find(response_keys, "CHAP_A");
 623         if (chap_a == NULL)
 624                 log_errx(1, "received CHAP packet without CHAP_A");
 625         chap_c = keys_find(response_keys, "CHAP_C");
 626         if (chap_c == NULL)
 627                 log_errx(1, "received CHAP packet without CHAP_C");
 628         chap_i = keys_find(response_keys, "CHAP_I");
 629         if (chap_i == NULL)
 630                 log_errx(1, "received CHAP packet without CHAP_I");
 631
 632         if (strcmp(chap_a, "5") != 0) {
 633                 log_errx(1, "received CHAP packet "
 634                     "with unsupported CHAP_A \"%s\"", chap_a);
 635         }
 636
 637         rchap = rchap_new(conn->conn_conf.isc_secret);
 638         error = rchap_receive(rchap, chap_i, chap_c);
 639         if (error != 0) {
 640                 log_errx(1, "received CHAP packet "
 641                     "with malformed CHAP_I or CHAP_C");
 642         }
 643         chap_r = rchap_get_response(rchap);
 644         rchap_delete(rchap);
 645
 646         keys_delete(response_keys);
 647
 648         request = login_new_request(conn, BHSLR_STAGE_SECURITY_NEGOTIATION);
 649         request_keys = keys_new();
 650         keys_add(request_keys, "CHAP_N", conn->conn_conf.isc_user);
 651         keys_add(request_keys, "CHAP_R", chap_r);
 652         free(chap_r);
 653
 654         /*
 655          * If we want mutual authentication, we're expected to send
 656          * our CHAP_I/CHAP_C now.
 657          */
 658         if (conn->conn_conf.isc_mutual_user[0] != '\0') {
 659                 log_debugx("requesting mutual authentication; "
 660                     "binary challenge size is %zd bytes",
 661                     sizeof(conn->conn_mutual_chap->chap_challenge));
 662
 663                 assert(conn->conn_mutual_chap == NULL);
 664                 conn->conn_mutual_chap = chap_new();
 665                 mutual_chap_i = chap_get_id(conn->conn_mutual_chap);
 666                 mutual_chap_c = chap_get_challenge(conn->conn_mutual_chap);
 667                 keys_add(request_keys, "CHAP_I", mutual_chap_i);
 668                 keys_add(request_keys, "CHAP_C", mutual_chap_c);
 669                 free(mutual_chap_i);
 670                 free(mutual_chap_c);
 671         }
 672
 673         keys_save(request_keys, request);
 674         keys_delete(request_keys);
 675         pdu_send(request);
 676         pdu_delete(request);
 677 }
 678
 679 static void
 680 login_verify_mutual(const struct pdu *response)
 681 {
 682         struct connection *conn;
 683         struct keys *response_keys;
 684         const char *chap_n, *chap_r;
 685         int error;
 686
 687         conn = response->pdu_connection;
 688
 689         response_keys = keys_new();
 690         keys_load(response_keys, response);
 691
 692         chap_n = keys_find(response_keys, "CHAP_N");
 693         if (chap_n == NULL)
 694                 log_errx(1, "received CHAP Response PDU without CHAP_N");
 695         chap_r = keys_find(response_keys, "CHAP_R");
 696         if (chap_r == NULL)
 697                 log_errx(1, "received CHAP Response PDU without CHAP_R");
 698
 699         error = chap_receive(conn->conn_mutual_chap, chap_r);
 700         if (error != 0)
 701                 log_errx(1, "received CHAP Response PDU with invalid CHAP_R");
 702
 703         if (strcmp(chap_n, conn->conn_conf.isc_mutual_user) != 0) {
 704                 fail(conn, "Mutual CHAP failed");
 705                 log_errx(1, "mutual CHAP authentication failed: wrong user");
 706         }
 707
 708         error = chap_authenticate(conn->conn_mutual_chap,
 709             conn->conn_conf.isc_mutual_secret);
 710         if (error != 0) {
 711                 fail(conn, "Mutual CHAP failed");
 712                 log_errx(1, "mutual CHAP authentication failed: wrong secret");
 713         }
 714
 715         keys_delete(response_keys);
 716         chap_delete(conn->conn_mutual_chap);
 717         conn->conn_mutual_chap = NULL;
 718
 719         log_debugx("mutual CHAP authentication succeeded");
 720 }
 721
 722 static void
 723 login_chap(struct connection *conn)
 724 {
 725         struct pdu *response;
 726
 727         log_debugx("beginning CHAP authentication; sending CHAP_A");
 728         login_send_chap_a(conn);
 729
 730         log_debugx("waiting for CHAP_A/CHAP_C/CHAP_I");
 731         response = login_receive(conn);
 732
 733         log_debugx("sending CHAP_N/CHAP_R");
 734         login_send_chap_r(response);
 735         pdu_delete(response);
 736
 737         /*
 738          * XXX: Make sure this is not susceptible to MITM.
 739          */
 740
 741         log_debugx("waiting for CHAP result");
 742         response = login_receive(conn);
 743         if (conn->conn_conf.isc_mutual_user[0] != '\0')
 744                 login_verify_mutual(response);
 745         pdu_delete(response);
 746
 747         log_debugx("CHAP authentication done");
 748 }
 749
 750 void
 751 login(struct connection *conn)
 752 {
 753         struct pdu *request, *response;
 754         struct keys *request_keys, *response_keys;
 755         struct iscsi_bhs_login_response *bhslr2;
 756         const char *auth_method;
 757         int i;
 758
 759         log_debugx("beginning Login phase; sending Login PDU");
 760         request = login_new_request(conn, BHSLR_STAGE_SECURITY_NEGOTIATION);
 761         request_keys = keys_new();
 762         if (conn->conn_conf.isc_mutual_user[0] != '\0') {
 763                 keys_add(request_keys, "AuthMethod", "CHAP");
 764         } else if (conn->conn_conf.isc_user[0] != '\0') {
 765                 /*
 766                  * Give target a chance to skip authentication if it
 767                  * doesn't feel like it.
 768                  *
 769                  * None is first, CHAP second; this is to work around
 770                  * what seems to be LIO (Linux target) bug: otherwise,
 771                  * if target is configured with no authentication,
 772                  * and we are configured to authenticate, the target
 773                  * will erroneously respond with AuthMethod=CHAP
 774                  * instead of AuthMethod=None, and will subsequently
 775                  * fail the connection.  This usually happens with
 776                  * Discovery sessions, which default to no authentication.
 777                  */
 778                 keys_add(request_keys, "AuthMethod", "None,CHAP");
 779         } else {
 780                 keys_add(request_keys, "AuthMethod", "None");
 781         }
 782         keys_add(request_keys, "InitiatorName",
 783             conn->conn_conf.isc_initiator);
 784         if (conn->conn_conf.isc_initiator_alias[0] != '\0') {
 785                 keys_add(request_keys, "InitiatorAlias",
 786                     conn->conn_conf.isc_initiator_alias);
 787         }
 788         if (conn->conn_conf.isc_discovery == 0) {
 789                 keys_add(request_keys, "SessionType", "Normal");
 790                 keys_add(request_keys,
 791                     "TargetName", conn->conn_conf.isc_target);
 792         } else {
 793                 keys_add(request_keys, "SessionType", "Discovery");
 794         }
 795         keys_save(request_keys, request);
 796         keys_delete(request_keys);
 797         pdu_send(request);
 798         pdu_delete(request);
 799
 800         response = login_receive(conn);
 801
 802         response_keys = keys_new();
 803         keys_load(response_keys, response);
 804
 805         for (i = 0; i < KEYS_MAX; i++) {
 806                 if (response_keys->keys_names[i] == NULL)
 807                         break;
 808
 809                 /*
 810                  * Not interested in AuthMethod at this point; we only need
 811                  * to parse things such as TargetAlias.
 812                  *
 813                  * XXX: This is somewhat ugly.  We should have a way to apply
 814                  *      all the keys to the session and use that by default
 815                  *      instead of discarding them.
 816                  */
 817                 if (strcmp(response_keys->keys_names[i], "AuthMethod") == 0)
 818                         continue;
 819
 820                 login_negotiate_key(conn,
 821                     response_keys->keys_names[i], response_keys->keys_values[i]);
 822         }
 823
 824         bhslr2 = (struct iscsi_bhs_login_response *)response->pdu_bhs;
 825         if ((bhslr2->bhslr_flags & BHSLR_FLAGS_TRANSIT) != 0 &&
 826             login_nsg(response) == BHSLR_STAGE_OPERATIONAL_NEGOTIATION) {
 827                 if (conn->conn_conf.isc_mutual_user[0] != '\0') {
 828                         log_errx(1, "target requested transition "
 829                             "to operational parameter negotiation, "
 830                             "but we require mutual CHAP");
 831                 }
 832
 833                 log_debugx("target requested transition "
 834                     "to operational parameter negotiation");
 835                 keys_delete(response_keys);
 836                 pdu_delete(response);
 837                 login_negotiate(conn);
 838                 return;
 839         }
 840
 841         auth_method = keys_find(response_keys, "AuthMethod");
 842         if (auth_method == NULL)
 843                 log_errx(1, "received response without AuthMethod");
 844         if (strcmp(auth_method, "None") == 0) {
 845                 if (conn->conn_conf.isc_mutual_user[0] != '\0') {
 846                         log_errx(1, "target does not require authantication, "
 847                             "but we require mutual CHAP");
 848                 }
 849
 850                 log_debugx("target does not require authentication");
 851                 keys_delete(response_keys);
 852                 pdu_delete(response);
 853                 login_negotiate(conn);
 854                 return;
 855         }
 856
 857         if (strcmp(auth_method, "CHAP") != 0) {
 858                 fail(conn, "Unsupported AuthMethod");
 859                 log_errx(1, "received response "
 860                     "with unsupported AuthMethod \"%s\"", auth_method);
 861         }
 862
 863         if (conn->conn_conf.isc_user[0] == '\0' ||
 864             conn->conn_conf.isc_secret[0] == '\0') {
 865                 fail(conn, "Authentication required");
 866                 log_errx(1, "target requests CHAP authentication, but we don't "
 867                     "have user and secret");
 868         }
 869
 870         keys_delete(response_keys);
 871         response_keys = NULL;
 872         pdu_delete(response);
 873         response = NULL;
 874
 875         login_chap(conn);
 876         login_negotiate(conn);
 877 }