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         struct iscsi_session_limits *isl;
 336         int which, tmp;
 337
 338         isl = &conn->conn_limits;
 339         if (strcmp(name, "TargetAlias") == 0) {
 340                 strlcpy(conn->conn_target_alias, value,
 341                     sizeof(conn->conn_target_alias));
 342         } else if (strcmp(value, "Irrelevant") == 0) {
 343                 /* Ignore. */
 344         } else if (strcmp(name, "HeaderDigest") == 0) {
 345                 which = login_list_prefers(value, "CRC32C", "None");
 346                 switch (which) {
 347                 case 1:
 348                         log_debugx("target prefers CRC32C "
 349                             "for header digest; we'll use it");
 350                         conn->conn_header_digest = CONN_DIGEST_CRC32C;
 351                         break;
 352                 case 2:
 353                         log_debugx("target prefers not to do "
 354                             "header digest; we'll comply");
 355                         break;
 356                 default:
 357                         log_warnx("target sent unrecognized "
 358                             "HeaderDigest value \"%s\"; will use None", value);
 359                         break;
 360                 }
 361         } else if (strcmp(name, "DataDigest") == 0) {
 362                 which = login_list_prefers(value, "CRC32C", "None");
 363                 switch (which) {
 364                 case 1:
 365                         log_debugx("target prefers CRC32C "
 366                             "for data digest; we'll use it");
 367                         conn->conn_data_digest = CONN_DIGEST_CRC32C;
 368                         break;
 369                 case 2:
 370                         log_debugx("target prefers not to do "
 371                             "data digest; we'll comply");
 372                         break;
 373                 default:
 374                         log_warnx("target sent unrecognized "
 375                             "DataDigest value \"%s\"; will use None", value);
 376                         break;
 377                 }
 378         } else if (strcmp(name, "MaxConnections") == 0) {
 379                 /* Ignore. */
 380         } else if (strcmp(name, "InitialR2T") == 0) {
 381                 if (strcmp(value, "Yes") == 0)
 382                         conn->conn_initial_r2t = true;
 383                 else
 384                         conn->conn_initial_r2t = false;
 385         } else if (strcmp(name, "ImmediateData") == 0) {
 386                 if (strcmp(value, "Yes") == 0)
 387                         conn->conn_immediate_data = true;
 388                 else
 389                         conn->conn_immediate_data = false;
 390         } else if (strcmp(name, "MaxRecvDataSegmentLength") == 0) {
 391                 tmp = strtoul(value, NULL, 10);
 392                 if (tmp <= 0)
 393                         log_errx(1, "received invalid "
 394                             "MaxRecvDataSegmentLength");
 395                 if (tmp > isl->isl_max_send_data_segment_length) {
 396                         log_debugx("capping max_send_data_segment_length "
 397                             "from %d to %d", tmp,
 398                             isl->isl_max_send_data_segment_length);
 399                         tmp = isl->isl_max_send_data_segment_length;
 400                 }
 401                 conn->conn_max_send_data_segment_length = tmp;
 402                 /* We received target's limit, that means it accepted our's. */
 403                 conn->conn_max_recv_data_segment_length =
 404                     isl->isl_max_recv_data_segment_length;
 405         } else if (strcmp(name, "MaxBurstLength") == 0) {
 406                 tmp = strtoul(value, NULL, 10);
 407                 if (tmp <= 0)
 408                         log_errx(1, "received invalid MaxBurstLength");
 409                 if (tmp > isl->isl_max_burst_length) {
 410                         log_debugx("capping MaxBurstLength "
 411                             "from %d to %d", tmp, isl->isl_max_burst_length);
 412                         tmp = isl->isl_max_burst_length;
 413                 }
 414                 conn->conn_max_burst_length = tmp;
 415         } else if (strcmp(name, "FirstBurstLength") == 0) {
 416                 tmp = strtoul(value, NULL, 10);
 417                 if (tmp <= 0)
 418                         log_errx(1, "received invalid FirstBurstLength");
 419                 if (tmp > isl->isl_first_burst_length) {
 420                         log_debugx("capping FirstBurstLength "
 421                             "from %d to %d", tmp, isl->isl_first_burst_length);
 422                         tmp = isl->isl_first_burst_length;
 423                 }
 424                 conn->conn_first_burst_length = tmp;
 425         } else if (strcmp(name, "DefaultTime2Wait") == 0) {
 426                 /* Ignore */
 427         } else if (strcmp(name, "DefaultTime2Retain") == 0) {
 428                 /* Ignore */
 429         } else if (strcmp(name, "MaxOutstandingR2T") == 0) {
 430                 /* Ignore */
 431         } else if (strcmp(name, "DataPDUInOrder") == 0) {
 432                 /* Ignore */
 433         } else if (strcmp(name, "DataSequenceInOrder") == 0) {
 434                 /* Ignore */
 435         } else if (strcmp(name, "ErrorRecoveryLevel") == 0) {
 436                 /* Ignore */
 437         } else if (strcmp(name, "OFMarker") == 0) {
 438                 /* Ignore */
 439         } else if (strcmp(name, "IFMarker") == 0) {
 440                 /* Ignore */
 441         } else if (strcmp(name, "RDMAExtensions") == 0) {
 442                 if (conn->conn_conf.isc_iser == 1 &&
 443                     strcmp(value, "Yes") != 0) {
 444                         log_errx(1, "received unsupported RDMAExtensions");
 445                 }
 446         } else if (strcmp(name, "InitiatorRecvDataSegmentLength") == 0) {
 447                 tmp = strtoul(value, NULL, 10);
 448                 if (tmp <= 0)
 449                         log_errx(1, "received invalid "
 450                             "InitiatorRecvDataSegmentLength");
 451                 if ((int)tmp > isl->isl_max_recv_data_segment_length) {
 452                         log_debugx("capping InitiatorRecvDataSegmentLength "
 453                             "from %d to %d", tmp,
 454                             isl->isl_max_recv_data_segment_length);
 455                         tmp = isl->isl_max_recv_data_segment_length;
 456                 }
 457                 conn->conn_max_recv_data_segment_length = tmp;
 458         } else if (strcmp(name, "TargetPortalGroupTag") == 0) {
 459                 /* Ignore */
 460         } else if (strcmp(name, "TargetRecvDataSegmentLength") == 0) {
 461                 tmp = strtoul(value, NULL, 10);
 462                 if (tmp <= 0) {
 463                         log_errx(1,
 464                             "received invalid TargetRecvDataSegmentLength");
 465                 }
 466                 if (tmp > isl->isl_max_send_data_segment_length) {
 467                         log_debugx("capping TargetRecvDataSegmentLength "
 468                             "from %d to %d", tmp,
 469                             isl->isl_max_send_data_segment_length);
 470                         tmp = isl->isl_max_send_data_segment_length;
 471                 }
 472                 conn->conn_max_send_data_segment_length = tmp;
 473         } else {
 474                 log_debugx("unknown key \"%s\"; ignoring",  name);
 475         }
 476 }
 477
 478 static void
 479 login_negotiate(struct connection *conn)
 480 {
 481         struct pdu *request, *response;
 482         struct keys *request_keys, *response_keys;
 483         struct iscsi_bhs_login_response *bhslr;
 484         int i, nrequests = 0;
 485         struct iscsi_session_limits *isl;
 486
 487         log_debugx("beginning operational parameter negotiation");
 488         request = login_new_request(conn, BHSLR_STAGE_OPERATIONAL_NEGOTIATION);
 489         request_keys = keys_new();
 490
 491         isl = &conn->conn_limits;
 492         log_debugx("Limits for offload \"%s\" are "
 493             "MaxRecvDataSegment=%d, max_send_dsl=%d, "
 494             "MaxBurstLength=%d, FirstBurstLength=%d",
 495             conn->conn_conf.isc_offload, isl->isl_max_recv_data_segment_length,
 496             isl->isl_max_send_data_segment_length, isl->isl_max_burst_length,
 497             isl->isl_first_burst_length);
 498
 499         /*
 500          * The following keys are irrelevant for discovery sessions.
 501          */
 502         if (conn->conn_conf.isc_discovery == 0) {
 503                 if (conn->conn_conf.isc_header_digest != 0)
 504                         keys_add(request_keys, "HeaderDigest", "CRC32C");
 505                 else
 506                         keys_add(request_keys, "HeaderDigest", "None");
 507                 if (conn->conn_conf.isc_data_digest != 0)
 508                         keys_add(request_keys, "DataDigest", "CRC32C");
 509                 else
 510                         keys_add(request_keys, "DataDigest", "None");
 511
 512                 keys_add(request_keys, "ImmediateData", "Yes");
 513                 keys_add_int(request_keys, "MaxBurstLength",
 514                     isl->isl_max_burst_length);
 515                 keys_add_int(request_keys, "FirstBurstLength",
 516                     isl->isl_first_burst_length);
 517                 keys_add(request_keys, "InitialR2T", "Yes");
 518                 keys_add(request_keys, "MaxOutstandingR2T", "1");
 519                 if (conn->conn_conf.isc_iser == 1) {
 520                         keys_add_int(request_keys, "InitiatorRecvDataSegmentLength",
 521                             isl->isl_max_recv_data_segment_length);
 522                         keys_add_int(request_keys, "TargetRecvDataSegmentLength",
 523                             isl->isl_max_send_data_segment_length);
 524                         keys_add(request_keys, "RDMAExtensions", "Yes");
 525                 } else {
 526                         keys_add_int(request_keys, "MaxRecvDataSegmentLength",
 527                             isl->isl_max_recv_data_segment_length);
 528                 }
 529         } else {
 530                 keys_add(request_keys, "HeaderDigest", "None");
 531                 keys_add(request_keys, "DataDigest", "None");
 532                 keys_add_int(request_keys, "MaxRecvDataSegmentLength",
 533                     isl->isl_max_recv_data_segment_length);
 534         }
 535
 536         keys_add(request_keys, "DefaultTime2Wait", "0");
 537         keys_add(request_keys, "DefaultTime2Retain", "0");
 538         keys_add(request_keys, "ErrorRecoveryLevel", "0");
 539         keys_save(request_keys, request);
 540         keys_delete(request_keys);
 541         request_keys = NULL;
 542         pdu_send(request);
 543         pdu_delete(request);
 544         request = NULL;
 545
 546         response = login_receive(conn);
 547         response_keys = keys_new();
 548         keys_load(response_keys, response);
 549         for (i = 0; i < KEYS_MAX; i++) {
 550                 if (response_keys->keys_names[i] == NULL)
 551                         break;
 552
 553                 login_negotiate_key(conn,
 554                     response_keys->keys_names[i], response_keys->keys_values[i]);
 555         }
 556
 557         keys_delete(response_keys);
 558         response_keys = NULL;
 559
 560         for (;;) {
 561                 bhslr = (struct iscsi_bhs_login_response *)response->pdu_bhs;
 562                 if ((bhslr->bhslr_flags & BHSLR_FLAGS_TRANSIT) != 0)
 563                         break;
 564
 565                 nrequests++;
 566                 if (nrequests > 5) {
 567                         log_warnx("received login response "
 568                             "without the \"T\" flag too many times; giving up");
 569                         break;
 570                 }
 571
 572                 log_debugx("received login response "
 573                     "without the \"T\" flag; sending another request");
 574
 575                 pdu_delete(response);
 576
 577                 request = login_new_request(conn,
 578                     BHSLR_STAGE_OPERATIONAL_NEGOTIATION);
 579                 pdu_send(request);
 580                 pdu_delete(request);
 581
 582                 response = login_receive(conn);
 583         }
 584
 585         if (login_nsg(response) != BHSLR_STAGE_FULL_FEATURE_PHASE)
 586                 log_warnx("received final login response with wrong NSG 0x%x",
 587                     login_nsg(response));
 588         pdu_delete(response);
 589
 590         log_debugx("operational parameter negotiation done; "
 591             "transitioning to Full Feature phase");
 592 }
 593
 594 static void
 595 login_send_chap_a(struct connection *conn)
 596 {
 597         struct pdu *request;
 598         struct keys *request_keys;
 599
 600         request = login_new_request(conn, BHSLR_STAGE_SECURITY_NEGOTIATION);
 601         request_keys = keys_new();
 602         keys_add(request_keys, "CHAP_A", "5");
 603         keys_save(request_keys, request);
 604         keys_delete(request_keys);
 605         pdu_send(request);
 606         pdu_delete(request);
 607 }
 608
 609 static void
 610 login_send_chap_r(struct pdu *response)
 611 {
 612         struct connection *conn;
 613         struct pdu *request;
 614         struct keys *request_keys, *response_keys;
 615         struct rchap *rchap;
 616         const char *chap_a, *chap_c, *chap_i;
 617         char *chap_r;
 618         int error;
 619         char *mutual_chap_c, *mutual_chap_i;
 620
 621         /*
 622          * As in the rest of the initiator, 'request' means
 623          * 'initiator -> target', and 'response' means 'target -> initiator',
 624          *
 625          * So, here the 'response' from the target is the packet that contains
 626          * CHAP challenge; our CHAP response goes into 'request'.
 627          */
 628
 629         conn = response->pdu_connection;
 630
 631         response_keys = keys_new();
 632         keys_load(response_keys, response);
 633
 634         /*
 635          * First, compute the response.
 636          */
 637         chap_a = keys_find(response_keys, "CHAP_A");
 638         if (chap_a == NULL)
 639                 log_errx(1, "received CHAP packet without CHAP_A");
 640         chap_c = keys_find(response_keys, "CHAP_C");
 641         if (chap_c == NULL)
 642                 log_errx(1, "received CHAP packet without CHAP_C");
 643         chap_i = keys_find(response_keys, "CHAP_I");
 644         if (chap_i == NULL)
 645                 log_errx(1, "received CHAP packet without CHAP_I");
 646
 647         if (strcmp(chap_a, "5") != 0) {
 648                 log_errx(1, "received CHAP packet "
 649                     "with unsupported CHAP_A \"%s\"", chap_a);
 650         }
 651
 652         rchap = rchap_new(conn->conn_conf.isc_secret);
 653         error = rchap_receive(rchap, chap_i, chap_c);
 654         if (error != 0) {
 655                 log_errx(1, "received CHAP packet "
 656                     "with malformed CHAP_I or CHAP_C");
 657         }
 658         chap_r = rchap_get_response(rchap);
 659         rchap_delete(rchap);
 660
 661         keys_delete(response_keys);
 662
 663         request = login_new_request(conn, BHSLR_STAGE_SECURITY_NEGOTIATION);
 664         request_keys = keys_new();
 665         keys_add(request_keys, "CHAP_N", conn->conn_conf.isc_user);
 666         keys_add(request_keys, "CHAP_R", chap_r);
 667         free(chap_r);
 668
 669         /*
 670          * If we want mutual authentication, we're expected to send
 671          * our CHAP_I/CHAP_C now.
 672          */
 673         if (conn->conn_conf.isc_mutual_user[0] != '\0') {
 674                 log_debugx("requesting mutual authentication; "
 675                     "binary challenge size is %zd bytes",
 676                     sizeof(conn->conn_mutual_chap->chap_challenge));
 677
 678                 assert(conn->conn_mutual_chap == NULL);
 679                 conn->conn_mutual_chap = chap_new();
 680                 mutual_chap_i = chap_get_id(conn->conn_mutual_chap);
 681                 mutual_chap_c = chap_get_challenge(conn->conn_mutual_chap);
 682                 keys_add(request_keys, "CHAP_I", mutual_chap_i);
 683                 keys_add(request_keys, "CHAP_C", mutual_chap_c);
 684                 free(mutual_chap_i);
 685                 free(mutual_chap_c);
 686         }
 687
 688         keys_save(request_keys, request);
 689         keys_delete(request_keys);
 690         pdu_send(request);
 691         pdu_delete(request);
 692 }
 693
 694 static void
 695 login_verify_mutual(const struct pdu *response)
 696 {
 697         struct connection *conn;
 698         struct keys *response_keys;
 699         const char *chap_n, *chap_r;
 700         int error;
 701
 702         conn = response->pdu_connection;
 703
 704         response_keys = keys_new();
 705         keys_load(response_keys, response);
 706
 707         chap_n = keys_find(response_keys, "CHAP_N");
 708         if (chap_n == NULL)
 709                 log_errx(1, "received CHAP Response PDU without CHAP_N");
 710         chap_r = keys_find(response_keys, "CHAP_R");
 711         if (chap_r == NULL)
 712                 log_errx(1, "received CHAP Response PDU without CHAP_R");
 713
 714         error = chap_receive(conn->conn_mutual_chap, chap_r);
 715         if (error != 0)
 716                 log_errx(1, "received CHAP Response PDU with invalid CHAP_R");
 717
 718         if (strcmp(chap_n, conn->conn_conf.isc_mutual_user) != 0) {
 719                 fail(conn, "Mutual CHAP failed");
 720                 log_errx(1, "mutual CHAP authentication failed: wrong user");
 721         }
 722
 723         error = chap_authenticate(conn->conn_mutual_chap,
 724             conn->conn_conf.isc_mutual_secret);
 725         if (error != 0) {
 726                 fail(conn, "Mutual CHAP failed");
 727                 log_errx(1, "mutual CHAP authentication failed: wrong secret");
 728         }
 729
 730         keys_delete(response_keys);
 731         chap_delete(conn->conn_mutual_chap);
 732         conn->conn_mutual_chap = NULL;
 733
 734         log_debugx("mutual CHAP authentication succeeded");
 735 }
 736
 737 static void
 738 login_chap(struct connection *conn)
 739 {
 740         struct pdu *response;
 741
 742         log_debugx("beginning CHAP authentication; sending CHAP_A");
 743         login_send_chap_a(conn);
 744
 745         log_debugx("waiting for CHAP_A/CHAP_C/CHAP_I");
 746         response = login_receive(conn);
 747
 748         log_debugx("sending CHAP_N/CHAP_R");
 749         login_send_chap_r(response);
 750         pdu_delete(response);
 751
 752         /*
 753          * XXX: Make sure this is not susceptible to MITM.
 754          */
 755
 756         log_debugx("waiting for CHAP result");
 757         response = login_receive(conn);
 758         if (conn->conn_conf.isc_mutual_user[0] != '\0')
 759                 login_verify_mutual(response);
 760         pdu_delete(response);
 761
 762         log_debugx("CHAP authentication done");
 763 }
 764
 765 void
 766 login(struct connection *conn)
 767 {
 768         struct pdu *request, *response;
 769         struct keys *request_keys, *response_keys;
 770         struct iscsi_bhs_login_response *bhslr2;
 771         const char *auth_method;
 772         int i;
 773
 774         log_debugx("beginning Login phase; sending Login PDU");
 775         request = login_new_request(conn, BHSLR_STAGE_SECURITY_NEGOTIATION);
 776         request_keys = keys_new();
 777         if (conn->conn_conf.isc_mutual_user[0] != '\0') {
 778                 keys_add(request_keys, "AuthMethod", "CHAP");
 779         } else if (conn->conn_conf.isc_user[0] != '\0') {
 780                 /*
 781                  * Give target a chance to skip authentication if it
 782                  * doesn't feel like it.
 783                  *
 784                  * None is first, CHAP second; this is to work around
 785                  * what seems to be LIO (Linux target) bug: otherwise,
 786                  * if target is configured with no authentication,
 787                  * and we are configured to authenticate, the target
 788                  * will erroneously respond with AuthMethod=CHAP
 789                  * instead of AuthMethod=None, and will subsequently
 790                  * fail the connection.  This usually happens with
 791                  * Discovery sessions, which default to no authentication.
 792                  */
 793                 keys_add(request_keys, "AuthMethod", "None,CHAP");
 794         } else {
 795                 keys_add(request_keys, "AuthMethod", "None");
 796         }
 797         keys_add(request_keys, "InitiatorName",
 798             conn->conn_conf.isc_initiator);
 799         if (conn->conn_conf.isc_initiator_alias[0] != '\0') {
 800                 keys_add(request_keys, "InitiatorAlias",
 801                     conn->conn_conf.isc_initiator_alias);
 802         }
 803         if (conn->conn_conf.isc_discovery == 0) {
 804                 keys_add(request_keys, "SessionType", "Normal");
 805                 keys_add(request_keys,
 806                     "TargetName", conn->conn_conf.isc_target);
 807         } else {
 808                 keys_add(request_keys, "SessionType", "Discovery");
 809         }
 810         keys_save(request_keys, request);
 811         keys_delete(request_keys);
 812         pdu_send(request);
 813         pdu_delete(request);
 814
 815         response = login_receive(conn);
 816
 817         response_keys = keys_new();
 818         keys_load(response_keys, response);
 819
 820         for (i = 0; i < KEYS_MAX; i++) {
 821                 if (response_keys->keys_names[i] == NULL)
 822                         break;
 823
 824                 /*
 825                  * Not interested in AuthMethod at this point; we only need
 826                  * to parse things such as TargetAlias.
 827                  *
 828                  * XXX: This is somewhat ugly.  We should have a way to apply
 829                  *      all the keys to the session and use that by default
 830                  *      instead of discarding them.
 831                  */
 832                 if (strcmp(response_keys->keys_names[i], "AuthMethod") == 0)
 833                         continue;
 834
 835                 login_negotiate_key(conn,
 836                     response_keys->keys_names[i], response_keys->keys_values[i]);
 837         }
 838
 839         bhslr2 = (struct iscsi_bhs_login_response *)response->pdu_bhs;
 840         if ((bhslr2->bhslr_flags & BHSLR_FLAGS_TRANSIT) != 0 &&
 841             login_nsg(response) == BHSLR_STAGE_OPERATIONAL_NEGOTIATION) {
 842                 if (conn->conn_conf.isc_mutual_user[0] != '\0') {
 843                         log_errx(1, "target requested transition "
 844                             "to operational parameter negotiation, "
 845                             "but we require mutual CHAP");
 846                 }
 847
 848                 log_debugx("target requested transition "
 849                     "to operational parameter negotiation");
 850                 keys_delete(response_keys);
 851                 pdu_delete(response);
 852                 login_negotiate(conn);
 853                 return;
 854         }
 855
 856         auth_method = keys_find(response_keys, "AuthMethod");
 857         if (auth_method == NULL)
 858                 log_errx(1, "received response without AuthMethod");
 859         if (strcmp(auth_method, "None") == 0) {
 860                 if (conn->conn_conf.isc_mutual_user[0] != '\0') {
 861                         log_errx(1, "target does not require authantication, "
 862                             "but we require mutual CHAP");
 863                 }
 864
 865                 log_debugx("target does not require authentication");
 866                 keys_delete(response_keys);
 867                 pdu_delete(response);
 868                 login_negotiate(conn);
 869                 return;
 870         }
 871
 872         if (strcmp(auth_method, "CHAP") != 0) {
 873                 fail(conn, "Unsupported AuthMethod");
 874                 log_errx(1, "received response "
 875                     "with unsupported AuthMethod \"%s\"", auth_method);
 876         }
 877
 878         if (conn->conn_conf.isc_user[0] == '\0' ||
 879             conn->conn_conf.isc_secret[0] == '\0') {
 880                 fail(conn, "Authentication required");
 881                 log_errx(1, "target requests CHAP authentication, but we don't "
 882                     "have user and secret");
 883         }
 884
 885         keys_delete(response_keys);
 886         response_keys = NULL;
 887         pdu_delete(response);
 888         response = NULL;
 889
 890         login_chap(conn);
 891         login_negotiate(conn);
 892 }