usr.sbin/iscsid/login.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
   3  *
   4  * Copyright (c) 2012 The FreeBSD Foundation
   5  * All rights reserved.
   6  *
   7  * This software was developed by Edward Tomasz Napierala under sponsorship
   8  * from the FreeBSD Foundation.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  *
  31  */
  32
  33 #include <sys/cdefs.h>
  34 __FBSDID("$FreeBSD$");
  35
  36 #include <sys/types.h>
  37 #include <sys/ioctl.h>
  38 #include <assert.h>
  39 #include <stdbool.h>
  40 #include <stdio.h>
  41 #include <stdlib.h>
  42 #include <string.h>
  43 #include <netinet/in.h>
  44
  45 #include "iscsid.h"
  46 #include "iscsi_proto.h"
  47
  48 static int
  49 login_nsg(const struct pdu *response)
  50 {
  51         struct iscsi_bhs_login_response *bhslr;
  52
  53         bhslr = (struct iscsi_bhs_login_response *)response->pdu_bhs;
  54
  55         return (bhslr->bhslr_flags & 0x03);
  56 }
  57
  58 static void
  59 login_set_nsg(struct pdu *request, int nsg)
  60 {
  61         struct iscsi_bhs_login_request *bhslr;
  62
  63         assert(nsg == BHSLR_STAGE_SECURITY_NEGOTIATION ||
  64             nsg == BHSLR_STAGE_OPERATIONAL_NEGOTIATION ||
  65             nsg == BHSLR_STAGE_FULL_FEATURE_PHASE);
  66
  67         bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs;
  68
  69         bhslr->bhslr_flags &= 0xFC;
  70         bhslr->bhslr_flags |= nsg;
  71 }
  72
  73 static void
  74 login_set_csg(struct pdu *request, int csg)
  75 {
  76         struct iscsi_bhs_login_request *bhslr;
  77
  78         assert(csg == BHSLR_STAGE_SECURITY_NEGOTIATION ||
  79             csg == BHSLR_STAGE_OPERATIONAL_NEGOTIATION ||
  80             csg == BHSLR_STAGE_FULL_FEATURE_PHASE);
  81
  82         bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs;
  83
  84         bhslr->bhslr_flags &= 0xF3;
  85         bhslr->bhslr_flags |= csg << 2;
  86 }
  87
  88 static const char *
  89 login_target_error_str(int class, int detail)
  90 {
  91         static char msg[128];
  92
  93         /*
  94          * RFC 3270, 10.13.5.  Status-Class and Status-Detail
  95          */
  96         switch (class) {
  97         case 0x01:
  98                 switch (detail) {
  99                 case 0x01:
 100                         return ("Target moved temporarily");
 101                 case 0x02:
 102                         return ("Target moved permanently");
 103                 default:
 104                         snprintf(msg, sizeof(msg), "unknown redirection; "
 105                             "Status-Class 0x%x, Status-Detail 0x%x",
 106                             class, detail);
 107                         return (msg);
 108                 }
 109         case 0x02:
 110                 switch (detail) {
 111                 case 0x00:
 112                         return ("Initiator error");
 113                 case 0x01:
 114                         return ("Authentication failure");
 115                 case 0x02:
 116                         return ("Authorization failure");
 117                 case 0x03:
 118                         return ("Not found");
 119                 case 0x04:
 120                         return ("Target removed");
 121                 case 0x05:
 122                         return ("Unsupported version");
 123                 case 0x06:
 124                         return ("Too many connections");
 125                 case 0x07:
 126                         return ("Missing parameter");
 127                 case 0x08:
 128                         return ("Can't include in session");
 129                 case 0x09:
 130                         return ("Session type not supported");
 131                 case 0x0a:
 132                         return ("Session does not exist");
 133                 case 0x0b:
 134                         return ("Invalid during login");
 135                 default:
 136                         snprintf(msg, sizeof(msg), "unknown initiator error; "
 137                             "Status-Class 0x%x, Status-Detail 0x%x",
 138                             class, detail);
 139                         return (msg);
 140                 }
 141         case 0x03:
 142                 switch (detail) {
 143                 case 0x00:
 144                         return ("Target error");
 145                 case 0x01:
 146                         return ("Service unavailable");
 147                 case 0x02:
 148                         return ("Out of resources");
 149                 default:
 150                         snprintf(msg, sizeof(msg), "unknown target error; "
 151                             "Status-Class 0x%x, Status-Detail 0x%x",
 152                             class, detail);
 153                         return (msg);
 154                 }
 155         default:
 156                 snprintf(msg, sizeof(msg), "unknown error; "
 157                     "Status-Class 0x%x, Status-Detail 0x%x",
 158                     class, detail);
 159                 return (msg);
 160         }
 161 }
 162
 163 static void
 164 kernel_modify(const struct connection *conn, const char *target_address)
 165 {
 166         struct iscsi_session_modify ism;
 167         int error;
 168
 169         memset(&ism, 0, sizeof(ism));
 170         ism.ism_session_id = conn->conn_session_id;
 171         memcpy(&ism.ism_conf, &conn->conn_conf, sizeof(ism.ism_conf));
 172         strlcpy(ism.ism_conf.isc_target_addr, target_address,
 173             sizeof(ism.ism_conf.isc_target));
 174         error = ioctl(conn->conn_iscsi_fd, ISCSISMODIFY, &ism);
 175         if (error != 0) {
 176                 log_err(1, "failed to redirect to %s: ISCSISMODIFY",
 177                     target_address);
 178         }
 179 }
 180
 181 /*
 182  * XXX: The way it works is suboptimal; what should happen is described
 183  *      in draft-gilligan-iscsi-fault-tolerance-00.  That, however, would
 184  *      be much more complicated: we would need to keep "dependencies"
 185  *      for sessions, so that, in case described in draft and using draft
 186  *      terminology, we would have three sessions: one for discovery,
 187  *      one for initial target portal, and one for redirect portal.
 188  *      This would allow us to "backtrack" on connection failure,
 189  *      as described in draft.
 190  */
 191 static void
 192 login_handle_redirection(struct connection *conn, struct pdu *response)
 193 {
 194         struct iscsi_bhs_login_response *bhslr;
 195         struct keys *response_keys;
 196         const char *target_address;
 197
 198         bhslr = (struct iscsi_bhs_login_response *)response->pdu_bhs;
 199         assert (bhslr->bhslr_status_class == 1);
 200
 201         response_keys = keys_new();
 202         keys_load(response_keys, response);
 203
 204         target_address = keys_find(response_keys, "TargetAddress");
 205         if (target_address == NULL)
 206                 log_errx(1, "received redirection without TargetAddress");
 207         if (target_address[0] == '\0')
 208                 log_errx(1, "received redirection with empty TargetAddress");
 209         if (strlen(target_address) >=
 210             sizeof(conn->conn_conf.isc_target_addr) - 1)
 211                 log_errx(1, "received TargetAddress is too long");
 212
 213         log_debugx("received redirection to \"%s\"", target_address);
 214         kernel_modify(conn, target_address);
 215         keys_delete(response_keys);
 216 }
 217
 218 static struct pdu *
 219 login_receive(struct connection *conn)
 220 {
 221         struct pdu *response;
 222         struct iscsi_bhs_login_response *bhslr;
 223         const char *errorstr;
 224         static bool initial = true;
 225
 226         response = pdu_new(conn);
 227         pdu_receive(response);
 228         if (response->pdu_bhs->bhs_opcode != ISCSI_BHS_OPCODE_LOGIN_RESPONSE) {
 229                 log_errx(1, "protocol error: received invalid opcode 0x%x",
 230                     response->pdu_bhs->bhs_opcode);
 231         }
 232         bhslr = (struct iscsi_bhs_login_response *)response->pdu_bhs;
 233         /*
 234          * XXX: Implement the C flag some day.
 235          */
 236         if ((bhslr->bhslr_flags & BHSLR_FLAGS_CONTINUE) != 0)
 237                 log_errx(1, "received Login PDU with unsupported \"C\" flag");
 238         if (bhslr->bhslr_version_max != 0x00)
 239                 log_errx(1, "received Login PDU with unsupported "
 240                     "Version-max 0x%x", bhslr->bhslr_version_max);
 241         if (bhslr->bhslr_version_active != 0x00)
 242                 log_errx(1, "received Login PDU with unsupported "
 243                     "Version-active 0x%x", bhslr->bhslr_version_active);
 244         if (bhslr->bhslr_status_class == 1) {
 245                 login_handle_redirection(conn, response);
 246                 log_debugx("redirection handled; exiting");
 247                 exit(0);
 248         }
 249         if (bhslr->bhslr_status_class != 0) {
 250                 errorstr = login_target_error_str(bhslr->bhslr_status_class,
 251                     bhslr->bhslr_status_detail);
 252                 fail(conn, errorstr);
 253                 log_errx(1, "target returned error: %s", errorstr);
 254         }
 255         if (initial == false &&
 256             ntohl(bhslr->bhslr_statsn) != conn->conn_statsn + 1) {
 257                 /*
 258                  * It's a warning, not an error, to work around what seems
 259                  * to be bug in NetBSD iSCSI target.
 260                  */
 261                 log_warnx("received Login PDU with wrong StatSN: "
 262                     "is %u, should be %u", ntohl(bhslr->bhslr_statsn),
 263                     conn->conn_statsn + 1);
 264         }
 265         conn->conn_tsih = ntohs(bhslr->bhslr_tsih);
 266         conn->conn_statsn = ntohl(bhslr->bhslr_statsn);
 267
 268         initial = false;
 269
 270         return (response);
 271 }
 272
 273 static struct pdu *
 274 login_new_request(struct connection *conn, int csg)
 275 {
 276         struct pdu *request;
 277         struct iscsi_bhs_login_request *bhslr;
 278         int nsg;
 279
 280         request = pdu_new(conn);
 281         bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs;
 282         bhslr->bhslr_opcode = ISCSI_BHS_OPCODE_LOGIN_REQUEST |
 283             ISCSI_BHS_OPCODE_IMMEDIATE;
 284
 285         bhslr->bhslr_flags = BHSLR_FLAGS_TRANSIT;
 286         switch (csg) {
 287         case BHSLR_STAGE_SECURITY_NEGOTIATION:
 288                 nsg = BHSLR_STAGE_OPERATIONAL_NEGOTIATION;
 289                 break;
 290         case BHSLR_STAGE_OPERATIONAL_NEGOTIATION:
 291                 nsg = BHSLR_STAGE_FULL_FEATURE_PHASE;
 292                 break;
 293         default:
 294                 assert(!"invalid csg");
 295                 log_errx(1, "invalid csg %d", csg);
 296         }
 297         login_set_csg(request, csg);
 298         login_set_nsg(request, nsg);
 299
 300         memcpy(bhslr->bhslr_isid, &conn->conn_isid, sizeof(bhslr->bhslr_isid));
 301         bhslr->bhslr_tsih = htons(conn->conn_tsih);
 302         bhslr->bhslr_initiator_task_tag = 0;
 303         bhslr->bhslr_cmdsn = 0;
 304         bhslr->bhslr_expstatsn = htonl(conn->conn_statsn + 1);
 305
 306         return (request);
 307 }
 308
 309 static int
 310 login_list_prefers(const char *list,
 311     const char *choice1, const char *choice2)
 312 {
 313         char *tofree, *str, *token;
 314
 315         tofree = str = checked_strdup(list);
 316
 317         while ((token = strsep(&str, ",")) != NULL) {
 318                 if (strcmp(token, choice1) == 0) {
 319                         free(tofree);
 320                         return (1);
 321                 }
 322                 if (strcmp(token, choice2) == 0) {
 323                         free(tofree);
 324                         return (2);
 325                 }
 326         }
 327         free(tofree);
 328         return (-1);
 329 }
 330
 331 static void
 332 login_negotiate_key(struct connection *conn, const char *name,
 333     const char *value)
 334 {
 335         int which, tmp;
 336
 337         if (strcmp(name, "TargetAlias") == 0) {
 338                 strlcpy(conn->conn_target_alias, value,
 339                     sizeof(conn->conn_target_alias));
 340         } else if (strcmp(value, "Irrelevant") == 0) {
 341                 /* Ignore. */
 342         } else if (strcmp(name, "HeaderDigest") == 0) {
 343                 which = login_list_prefers(value, "CRC32C", "None");
 344                 switch (which) {
 345                 case 1:
 346                         log_debugx("target prefers CRC32C "
 347                             "for header digest; we'll use it");
 348                         conn->conn_header_digest = CONN_DIGEST_CRC32C;
 349                         break;
 350                 case 2:
 351                         log_debugx("target prefers not to do "
 352                             "header digest; we'll comply");
 353                         break;
 354                 default:
 355                         log_warnx("target sent unrecognized "
 356                             "HeaderDigest value \"%s\"; will use None", value);
 357                         break;
 358                 }
 359         } else if (strcmp(name, "DataDigest") == 0) {
 360                 which = login_list_prefers(value, "CRC32C", "None");
 361                 switch (which) {
 362                 case 1:
 363                         log_debugx("target prefers CRC32C "
 364                             "for data digest; we'll use it");
 365                         conn->conn_data_digest = CONN_DIGEST_CRC32C;
 366                         break;
 367                 case 2:
 368                         log_debugx("target prefers not to do "
 369                             "data digest; we'll comply");
 370                         break;
 371                 default:
 372                         log_warnx("target sent unrecognized "
 373                             "DataDigest value \"%s\"; will use None", value);
 374                         break;
 375                 }
 376         } else if (strcmp(name, "MaxConnections") == 0) {
 377                 /* Ignore. */
 378         } else if (strcmp(name, "InitialR2T") == 0) {
 379                 if (strcmp(value, "Yes") == 0)
 380                         conn->conn_initial_r2t = true;
 381                 else
 382                         conn->conn_initial_r2t = false;
 383         } else if (strcmp(name, "ImmediateData") == 0) {
 384                 if (strcmp(value, "Yes") == 0)
 385                         conn->conn_immediate_data = true;
 386                 else
 387                         conn->conn_immediate_data = false;
 388         } else if (strcmp(name, "MaxRecvDataSegmentLength") == 0) {
 389                 tmp = strtoul(value, NULL, 10);
 390                 if (tmp <= 0)
 391                         log_errx(1, "received invalid "
 392                             "MaxRecvDataSegmentLength");
 393                 if (tmp > ISCSI_MAX_DATA_SEGMENT_LENGTH) {
 394                         log_debugx("capping MaxRecvDataSegmentLength "
 395                             "from %d to %d", tmp, ISCSI_MAX_DATA_SEGMENT_LENGTH);
 396                         tmp = ISCSI_MAX_DATA_SEGMENT_LENGTH;
 397                 }
 398                 conn->conn_max_data_segment_length = tmp;
 399         } else if (strcmp(name, "MaxBurstLength") == 0) {
 400                 tmp = strtoul(value, NULL, 10);
 401                 if (tmp <= 0)
 402                         log_errx(1, "received invalid MaxBurstLength");
 403                 if (tmp > MAX_BURST_LENGTH) {
 404                         log_debugx("capping MaxBurstLength "
 405                             "from %d to %d", tmp, MAX_BURST_LENGTH);
 406                         tmp = MAX_BURST_LENGTH;
 407                 }
 408                 conn->conn_max_burst_length = tmp;
 409         } else if (strcmp(name, "FirstBurstLength") == 0) {
 410                 tmp = strtoul(value, NULL, 10);
 411                 if (tmp <= 0)
 412                         log_errx(1, "received invalid FirstBurstLength");
 413                 if (tmp > FIRST_BURST_LENGTH) {
 414                         log_debugx("capping FirstBurstLength "
 415                             "from %d to %d", tmp, FIRST_BURST_LENGTH);
 416                         tmp = FIRST_BURST_LENGTH;
 417                 }
 418                 conn->conn_first_burst_length = tmp;
 419         } else if (strcmp(name, "DefaultTime2Wait") == 0) {
 420                 /* Ignore */
 421         } else if (strcmp(name, "DefaultTime2Retain") == 0) {
 422                 /* Ignore */
 423         } else if (strcmp(name, "MaxOutstandingR2T") == 0) {
 424                 /* Ignore */
 425         } else if (strcmp(name, "DataPDUInOrder") == 0) {
 426                 /* Ignore */
 427         } else if (strcmp(name, "DataSequenceInOrder") == 0) {
 428                 /* Ignore */
 429         } else if (strcmp(name, "ErrorRecoveryLevel") == 0) {
 430                 /* Ignore */
 431         } else if (strcmp(name, "OFMarker") == 0) {
 432                 /* Ignore */
 433         } else if (strcmp(name, "IFMarker") == 0) {
 434                 /* Ignore */
 435         } else if (strcmp(name, "RDMAExtensions") == 0) {
 436                 if (conn->conn_conf.isc_iser == 1 &&
 437                     strcmp(value, "Yes") != 0) {
 438                         log_errx(1, "received unsupported RDMAExtensions");
 439                 }
 440         } else if (strcmp(name, "InitiatorRecvDataSegmentLength") == 0) {
 441                 tmp = strtoul(value, NULL, 10);
 442                 if (tmp <= 0)
 443                         log_errx(1, "received invalid "
 444                             "InitiatorRecvDataSegmentLength");
 445                 if ((size_t)tmp > conn->conn_limits.isl_max_data_segment_length) {
 446                         log_debugx("capping InitiatorRecvDataSegmentLength "
 447                             "from %d to %zd", tmp,
 448                             conn->conn_limits.isl_max_data_segment_length);
 449                         tmp = conn->conn_limits.isl_max_data_segment_length;
 450                 }
 451                 conn->conn_max_data_segment_length = tmp;
 452         } else if (strcmp(name, "TargetPortalGroupTag") == 0) {
 453                 /* Ignore */
 454         } else if (strcmp(name, "TargetRecvDataSegmentLength") == 0) {
 455                 tmp = strtoul(value, NULL, 10);
 456                 if (tmp <= 0) {
 457                         log_errx(1,
 458                             "received invalid TargetRecvDataSegmentLength");
 459                 }
 460                 if ((size_t)tmp > conn->conn_limits.isl_max_data_segment_length) {
 461                         log_debugx("capping TargetRecvDataSegmentLength "
 462                             "from %d to %zd", tmp,
 463                             conn->conn_limits.isl_max_data_segment_length);
 464                         tmp = conn->conn_limits.isl_max_data_segment_length;
 465                 }
 466                 conn->conn_max_data_segment_length = tmp;
 467         } else {
 468                 log_debugx("unknown key \"%s\"; ignoring",  name);
 469         }
 470 }
 471
 472 static void
 473 login_negotiate(struct connection *conn)
 474 {
 475         struct pdu *request, *response;
 476         struct keys *request_keys, *response_keys;
 477         struct iscsi_bhs_login_response *bhslr;
 478         int i, nrequests = 0;
 479
 480         log_debugx("beginning operational parameter negotiation");
 481         request = login_new_request(conn, BHSLR_STAGE_OPERATIONAL_NEGOTIATION);
 482         request_keys = keys_new();
 483
 484         log_debugx("offload \"%s\" limits MaxRecvDataSegmentLength to %zd",
 485             conn->conn_conf.isc_offload,
 486             conn->conn_limits.isl_max_data_segment_length);
 487
 488         /*
 489          * The following keys are irrelevant for discovery sessions.
 490          */
 491         if (conn->conn_conf.isc_discovery == 0) {
 492                 if (conn->conn_conf.isc_header_digest != 0)
 493                         keys_add(request_keys, "HeaderDigest", "CRC32C");
 494                 else
 495                         keys_add(request_keys, "HeaderDigest", "None");
 496                 if (conn->conn_conf.isc_data_digest != 0)
 497                         keys_add(request_keys, "DataDigest", "CRC32C");
 498                 else
 499                         keys_add(request_keys, "DataDigest", "None");
 500
 501                 keys_add(request_keys, "ImmediateData", "Yes");
 502                 keys_add_int(request_keys, "MaxBurstLength", MAX_BURST_LENGTH);
 503                 keys_add_int(request_keys, "FirstBurstLength", FIRST_BURST_LENGTH);
 504                 keys_add(request_keys, "InitialR2T", "Yes");
 505                 keys_add(request_keys, "MaxOutstandingR2T", "1");
 506                 if (conn->conn_conf.isc_iser == 1) {
 507                         keys_add_int(request_keys, "InitiatorRecvDataSegmentLength",
 508                             conn->conn_limits.isl_max_data_segment_length);
 509                         keys_add_int(request_keys, "TargetRecvDataSegmentLength",
 510                             conn->conn_limits.isl_max_data_segment_length);
 511                         keys_add(request_keys, "RDMAExtensions", "Yes");
 512                 } else {
 513                         keys_add_int(request_keys, "MaxRecvDataSegmentLength",
 514                             conn->conn_limits.isl_max_data_segment_length);
 515                 }
 516         } else {
 517                 keys_add(request_keys, "HeaderDigest", "None");
 518                 keys_add(request_keys, "DataDigest", "None");
 519                 keys_add_int(request_keys, "MaxRecvDataSegmentLength",
 520                     conn->conn_limits.isl_max_data_segment_length);
 521         }
 522
 523         keys_add(request_keys, "DefaultTime2Wait", "0");
 524         keys_add(request_keys, "DefaultTime2Retain", "0");
 525         keys_add(request_keys, "ErrorRecoveryLevel", "0");
 526         keys_save(request_keys, request);
 527         keys_delete(request_keys);
 528         request_keys = NULL;
 529         pdu_send(request);
 530         pdu_delete(request);
 531         request = NULL;
 532
 533         response = login_receive(conn);
 534         response_keys = keys_new();
 535         keys_load(response_keys, response);
 536         for (i = 0; i < KEYS_MAX; i++) {
 537                 if (response_keys->keys_names[i] == NULL)
 538                         break;
 539
 540                 login_negotiate_key(conn,
 541                     response_keys->keys_names[i], response_keys->keys_values[i]);
 542         }
 543
 544         keys_delete(response_keys);
 545         response_keys = NULL;
 546
 547         for (;;) {
 548                 bhslr = (struct iscsi_bhs_login_response *)response->pdu_bhs;
 549                 if ((bhslr->bhslr_flags & BHSLR_FLAGS_TRANSIT) != 0)
 550                         break;
 551
 552                 nrequests++;
 553                 if (nrequests > 5) {
 554                         log_warnx("received login response "
 555                             "without the \"T\" flag too many times; giving up");
 556                         break;
 557                 }
 558
 559                 log_debugx("received login response "
 560                     "without the \"T\" flag; sending another request");
 561
 562                 pdu_delete(response);
 563
 564                 request = login_new_request(conn,
 565                     BHSLR_STAGE_OPERATIONAL_NEGOTIATION);
 566                 pdu_send(request);
 567                 pdu_delete(request);
 568
 569                 response = login_receive(conn);
 570         }
 571
 572         if (login_nsg(response) != BHSLR_STAGE_FULL_FEATURE_PHASE)
 573                 log_warnx("received final login response with wrong NSG 0x%x",
 574                     login_nsg(response));
 575         pdu_delete(response);
 576
 577         log_debugx("operational parameter negotiation done; "
 578             "transitioning to Full Feature phase");
 579 }
 580
 581 static void
 582 login_send_chap_a(struct connection *conn)
 583 {
 584         struct pdu *request;
 585         struct keys *request_keys;
 586
 587         request = login_new_request(conn, BHSLR_STAGE_SECURITY_NEGOTIATION);
 588         request_keys = keys_new();
 589         keys_add(request_keys, "CHAP_A", "5");
 590         keys_save(request_keys, request);
 591         keys_delete(request_keys);
 592         pdu_send(request);
 593         pdu_delete(request);
 594 }
 595
 596 static void
 597 login_send_chap_r(struct pdu *response)
 598 {
 599         struct connection *conn;
 600         struct pdu *request;
 601         struct keys *request_keys, *response_keys;
 602         struct rchap *rchap;
 603         const char *chap_a, *chap_c, *chap_i;
 604         char *chap_r;
 605         int error;
 606         char *mutual_chap_c, *mutual_chap_i;
 607
 608         /*
 609          * As in the rest of the initiator, 'request' means
 610          * 'initiator -> target', and 'response' means 'target -> initiator',
 611          *
 612          * So, here the 'response' from the target is the packet that contains
 613          * CHAP challenge; our CHAP response goes into 'request'.
 614          */
 615
 616         conn = response->pdu_connection;
 617
 618         response_keys = keys_new();
 619         keys_load(response_keys, response);
 620
 621         /*
 622          * First, compute the response.
 623          */
 624         chap_a = keys_find(response_keys, "CHAP_A");
 625         if (chap_a == NULL)
 626                 log_errx(1, "received CHAP packet without CHAP_A");
 627         chap_c = keys_find(response_keys, "CHAP_C");
 628         if (chap_c == NULL)
 629                 log_errx(1, "received CHAP packet without CHAP_C");
 630         chap_i = keys_find(response_keys, "CHAP_I");
 631         if (chap_i == NULL)
 632                 log_errx(1, "received CHAP packet without CHAP_I");
 633
 634         if (strcmp(chap_a, "5") != 0) {
 635                 log_errx(1, "received CHAP packet "
 636                     "with unsupported CHAP_A \"%s\"", chap_a);
 637         }
 638
 639         rchap = rchap_new(conn->conn_conf.isc_secret);
 640         error = rchap_receive(rchap, chap_i, chap_c);
 641         if (error != 0) {
 642                 log_errx(1, "received CHAP packet "
 643                     "with malformed CHAP_I or CHAP_C");
 644         }
 645         chap_r = rchap_get_response(rchap);
 646         rchap_delete(rchap);
 647
 648         keys_delete(response_keys);
 649
 650         request = login_new_request(conn, BHSLR_STAGE_SECURITY_NEGOTIATION);
 651         request_keys = keys_new();
 652         keys_add(request_keys, "CHAP_N", conn->conn_conf.isc_user);
 653         keys_add(request_keys, "CHAP_R", chap_r);
 654         free(chap_r);
 655
 656         /*
 657          * If we want mutual authentication, we're expected to send
 658          * our CHAP_I/CHAP_C now.
 659          */
 660         if (conn->conn_conf.isc_mutual_user[0] != '\0') {
 661                 log_debugx("requesting mutual authentication; "
 662                     "binary challenge size is %zd bytes",
 663                     sizeof(conn->conn_mutual_chap->chap_challenge));
 664
 665                 assert(conn->conn_mutual_chap == NULL);
 666                 conn->conn_mutual_chap = chap_new();
 667                 mutual_chap_i = chap_get_id(conn->conn_mutual_chap);
 668                 mutual_chap_c = chap_get_challenge(conn->conn_mutual_chap);
 669                 keys_add(request_keys, "CHAP_I", mutual_chap_i);
 670                 keys_add(request_keys, "CHAP_C", mutual_chap_c);
 671                 free(mutual_chap_i);
 672                 free(mutual_chap_c);
 673         }
 674
 675         keys_save(request_keys, request);
 676         keys_delete(request_keys);
 677         pdu_send(request);
 678         pdu_delete(request);
 679 }
 680
 681 static void
 682 login_verify_mutual(const struct pdu *response)
 683 {
 684         struct connection *conn;
 685         struct keys *response_keys;
 686         const char *chap_n, *chap_r;
 687         int error;
 688
 689         conn = response->pdu_connection;
 690
 691         response_keys = keys_new();
 692         keys_load(response_keys, response);
 693
 694         chap_n = keys_find(response_keys, "CHAP_N");
 695         if (chap_n == NULL)
 696                 log_errx(1, "received CHAP Response PDU without CHAP_N");
 697         chap_r = keys_find(response_keys, "CHAP_R");
 698         if (chap_r == NULL)
 699                 log_errx(1, "received CHAP Response PDU without CHAP_R");
 700
 701         error = chap_receive(conn->conn_mutual_chap, chap_r);
 702         if (error != 0)
 703                 log_errx(1, "received CHAP Response PDU with invalid CHAP_R");
 704
 705         if (strcmp(chap_n, conn->conn_conf.isc_mutual_user) != 0) {
 706                 fail(conn, "Mutual CHAP failed");
 707                 log_errx(1, "mutual CHAP authentication failed: wrong user");
 708         }
 709
 710         error = chap_authenticate(conn->conn_mutual_chap,
 711             conn->conn_conf.isc_mutual_secret);
 712         if (error != 0) {
 713                 fail(conn, "Mutual CHAP failed");
 714                 log_errx(1, "mutual CHAP authentication failed: wrong secret");
 715         }
 716
 717         keys_delete(response_keys);
 718         chap_delete(conn->conn_mutual_chap);
 719         conn->conn_mutual_chap = NULL;
 720
 721         log_debugx("mutual CHAP authentication succeeded");
 722 }
 723
 724 static void
 725 login_chap(struct connection *conn)
 726 {
 727         struct pdu *response;
 728
 729         log_debugx("beginning CHAP authentication; sending CHAP_A");
 730         login_send_chap_a(conn);
 731
 732         log_debugx("waiting for CHAP_A/CHAP_C/CHAP_I");
 733         response = login_receive(conn);
 734
 735         log_debugx("sending CHAP_N/CHAP_R");
 736         login_send_chap_r(response);
 737         pdu_delete(response);
 738
 739         /*
 740          * XXX: Make sure this is not susceptible to MITM.
 741          */
 742
 743         log_debugx("waiting for CHAP result");
 744         response = login_receive(conn);
 745         if (conn->conn_conf.isc_mutual_user[0] != '\0')
 746                 login_verify_mutual(response);
 747         pdu_delete(response);
 748
 749         log_debugx("CHAP authentication done");
 750 }
 751
 752 void
 753 login(struct connection *conn)
 754 {
 755         struct pdu *request, *response;
 756         struct keys *request_keys, *response_keys;
 757         struct iscsi_bhs_login_response *bhslr2;
 758         const char *auth_method;
 759         int i;
 760
 761         log_debugx("beginning Login phase; sending Login PDU");
 762         request = login_new_request(conn, BHSLR_STAGE_SECURITY_NEGOTIATION);
 763         request_keys = keys_new();
 764         if (conn->conn_conf.isc_mutual_user[0] != '\0') {
 765                 keys_add(request_keys, "AuthMethod", "CHAP");
 766         } else if (conn->conn_conf.isc_user[0] != '\0') {
 767                 /*
 768                  * Give target a chance to skip authentication if it
 769                  * doesn't feel like it.
 770                  *
 771                  * None is first, CHAP second; this is to work around
 772                  * what seems to be LIO (Linux target) bug: otherwise,
 773                  * if target is configured with no authentication,
 774                  * and we are configured to authenticate, the target
 775                  * will erroneously respond with AuthMethod=CHAP
 776                  * instead of AuthMethod=None, and will subsequently
 777                  * fail the connection.  This usually happens with
 778                  * Discovery sessions, which default to no authentication.
 779                  */
 780                 keys_add(request_keys, "AuthMethod", "None,CHAP");
 781         } else {
 782                 keys_add(request_keys, "AuthMethod", "None");
 783         }
 784         keys_add(request_keys, "InitiatorName",
 785             conn->conn_conf.isc_initiator);
 786         if (conn->conn_conf.isc_initiator_alias[0] != '\0') {
 787                 keys_add(request_keys, "InitiatorAlias",
 788                     conn->conn_conf.isc_initiator_alias);
 789         }
 790         if (conn->conn_conf.isc_discovery == 0) {
 791                 keys_add(request_keys, "SessionType", "Normal");
 792                 keys_add(request_keys,
 793                     "TargetName", conn->conn_conf.isc_target);
 794         } else {
 795                 keys_add(request_keys, "SessionType", "Discovery");
 796         }
 797         keys_save(request_keys, request);
 798         keys_delete(request_keys);
 799         pdu_send(request);
 800         pdu_delete(request);
 801
 802         response = login_receive(conn);
 803
 804         response_keys = keys_new();
 805         keys_load(response_keys, response);
 806
 807         for (i = 0; i < KEYS_MAX; i++) {
 808                 if (response_keys->keys_names[i] == NULL)
 809                         break;
 810
 811                 /*
 812                  * Not interested in AuthMethod at this point; we only need
 813                  * to parse things such as TargetAlias.
 814                  *
 815                  * XXX: This is somewhat ugly.  We should have a way to apply
 816                  *      all the keys to the session and use that by default
 817                  *      instead of discarding them.
 818                  */
 819                 if (strcmp(response_keys->keys_names[i], "AuthMethod") == 0)
 820                         continue;
 821
 822                 login_negotiate_key(conn,
 823                     response_keys->keys_names[i], response_keys->keys_values[i]);
 824         }
 825
 826         bhslr2 = (struct iscsi_bhs_login_response *)response->pdu_bhs;
 827         if ((bhslr2->bhslr_flags & BHSLR_FLAGS_TRANSIT) != 0 &&
 828             login_nsg(response) == BHSLR_STAGE_OPERATIONAL_NEGOTIATION) {
 829                 if (conn->conn_conf.isc_mutual_user[0] != '\0') {
 830                         log_errx(1, "target requested transition "
 831                             "to operational parameter negotiation, "
 832                             "but we require mutual CHAP");
 833                 }
 834
 835                 log_debugx("target requested transition "
 836                     "to operational parameter negotiation");
 837                 keys_delete(response_keys);
 838                 pdu_delete(response);
 839                 login_negotiate(conn);
 840                 return;
 841         }
 842
 843         auth_method = keys_find(response_keys, "AuthMethod");
 844         if (auth_method == NULL)
 845                 log_errx(1, "received response without AuthMethod");
 846         if (strcmp(auth_method, "None") == 0) {
 847                 if (conn->conn_conf.isc_mutual_user[0] != '\0') {
 848                         log_errx(1, "target does not require authantication, "
 849                             "but we require mutual CHAP");
 850                 }
 851
 852                 log_debugx("target does not require authentication");
 853                 keys_delete(response_keys);
 854                 pdu_delete(response);
 855                 login_negotiate(conn);
 856                 return;
 857         }
 858
 859         if (strcmp(auth_method, "CHAP") != 0) {
 860                 fail(conn, "Unsupported AuthMethod");
 861                 log_errx(1, "received response "
 862                     "with unsupported AuthMethod \"%s\"", auth_method);
 863         }
 864
 865         if (conn->conn_conf.isc_user[0] == '\0' ||
 866             conn->conn_conf.isc_secret[0] == '\0') {
 867                 fail(conn, "Authentication required");
 868                 log_errx(1, "target requests CHAP authentication, but we don't "
 869                     "have user and secret");
 870         }
 871
 872         keys_delete(response_keys);
 873         response_keys = NULL;
 874         pdu_delete(response);
 875         response = NULL;
 876
 877         login_chap(conn);
 878         login_negotiate(conn);
 879 }