usr.sbin/iscsid/login.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
   3  *
   4  * Copyright (c) 2012 The FreeBSD Foundation
   5  *
   6  * This software was developed by Edward Tomasz Napierala under sponsorship
   7  * from the FreeBSD Foundation.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in the
  16  *    documentation and/or other materials provided with the distribution.
  17  *
  18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  28  * SUCH DAMAGE.
  29  *
  30  */
  31
  32 #include <sys/cdefs.h>
  33 __FBSDID("$FreeBSD$");
  34
  35 #include <sys/types.h>
  36 #include <sys/ioctl.h>
  37 #include <assert.h>
  38 #include <stdbool.h>
  39 #include <stdio.h>
  40 #include <stdlib.h>
  41 #include <string.h>
  42 #include <netinet/in.h>
  43
  44 #include "iscsid.h"
  45 #include "iscsi_proto.h"
  46
  47 static int
  48 login_nsg(const struct pdu *response)
  49 {
  50         struct iscsi_bhs_login_response *bhslr;
  51
  52         bhslr = (struct iscsi_bhs_login_response *)response->pdu_bhs;
  53
  54         return (bhslr->bhslr_flags & 0x03);
  55 }
  56
  57 static void
  58 login_set_nsg(struct pdu *request, int nsg)
  59 {
  60         struct iscsi_bhs_login_request *bhslr;
  61
  62         assert(nsg == BHSLR_STAGE_SECURITY_NEGOTIATION ||
  63             nsg == BHSLR_STAGE_OPERATIONAL_NEGOTIATION ||
  64             nsg == BHSLR_STAGE_FULL_FEATURE_PHASE);
  65
  66         bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs;
  67
  68         bhslr->bhslr_flags &= 0xFC;
  69         bhslr->bhslr_flags |= nsg;
  70 }
  71
  72 static void
  73 login_set_csg(struct pdu *request, int csg)
  74 {
  75         struct iscsi_bhs_login_request *bhslr;
  76
  77         assert(csg == BHSLR_STAGE_SECURITY_NEGOTIATION ||
  78             csg == BHSLR_STAGE_OPERATIONAL_NEGOTIATION ||
  79             csg == BHSLR_STAGE_FULL_FEATURE_PHASE);
  80
  81         bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs;
  82
  83         bhslr->bhslr_flags &= 0xF3;
  84         bhslr->bhslr_flags |= csg << 2;
  85 }
  86
  87 static const char *
  88 login_target_error_str(int class, int detail)
  89 {
  90         static char msg[128];
  91
  92         /*
  93          * RFC 3270, 10.13.5.  Status-Class and Status-Detail
  94          */
  95         switch (class) {
  96         case 0x01:
  97                 switch (detail) {
  98                 case 0x01:
  99                         return ("Target moved temporarily");
 100                 case 0x02:
 101                         return ("Target moved permanently");
 102                 default:
 103                         snprintf(msg, sizeof(msg), "unknown redirection; "
 104                             "Status-Class 0x%x, Status-Detail 0x%x",
 105                             class, detail);
 106                         return (msg);
 107                 }
 108         case 0x02:
 109                 switch (detail) {
 110                 case 0x00:
 111                         return ("Initiator error");
 112                 case 0x01:
 113                         return ("Authentication failure");
 114                 case 0x02:
 115                         return ("Authorization failure");
 116                 case 0x03:
 117                         return ("Not found");
 118                 case 0x04:
 119                         return ("Target removed");
 120                 case 0x05:
 121                         return ("Unsupported version");
 122                 case 0x06:
 123                         return ("Too many connections");
 124                 case 0x07:
 125                         return ("Missing parameter");
 126                 case 0x08:
 127                         return ("Can't include in session");
 128                 case 0x09:
 129                         return ("Session type not supported");
 130                 case 0x0a:
 131                         return ("Session does not exist");
 132                 case 0x0b:
 133                         return ("Invalid during login");
 134                 default:
 135                         snprintf(msg, sizeof(msg), "unknown initiator error; "
 136                             "Status-Class 0x%x, Status-Detail 0x%x",
 137                             class, detail);
 138                         return (msg);
 139                 }
 140         case 0x03:
 141                 switch (detail) {
 142                 case 0x00:
 143                         return ("Target error");
 144                 case 0x01:
 145                         return ("Service unavailable");
 146                 case 0x02:
 147                         return ("Out of resources");
 148                 default:
 149                         snprintf(msg, sizeof(msg), "unknown target error; "
 150                             "Status-Class 0x%x, Status-Detail 0x%x",
 151                             class, detail);
 152                         return (msg);
 153                 }
 154         default:
 155                 snprintf(msg, sizeof(msg), "unknown error; "
 156                     "Status-Class 0x%x, Status-Detail 0x%x",
 157                     class, detail);
 158                 return (msg);
 159         }
 160 }
 161
 162 static void
 163 kernel_modify(const struct connection *conn, const char *target_address)
 164 {
 165         struct iscsi_session_modify ism;
 166         int error;
 167
 168         memset(&ism, 0, sizeof(ism));
 169         ism.ism_session_id = conn->conn_session_id;
 170         memcpy(&ism.ism_conf, &conn->conn_conf, sizeof(ism.ism_conf));
 171         strlcpy(ism.ism_conf.isc_target_addr, target_address,
 172             sizeof(ism.ism_conf.isc_target_addr));
 173         error = ioctl(conn->conn_iscsi_fd, ISCSISMODIFY, &ism);
 174         if (error != 0) {
 175                 log_err(1, "failed to redirect to %s: ISCSISMODIFY",
 176                     target_address);
 177         }
 178 }
 179
 180 /*
 181  * XXX: The way it works is suboptimal; what should happen is described
 182  *      in draft-gilligan-iscsi-fault-tolerance-00.  That, however, would
 183  *      be much more complicated: we would need to keep "dependencies"
 184  *      for sessions, so that, in case described in draft and using draft
 185  *      terminology, we would have three sessions: one for discovery,
 186  *      one for initial target portal, and one for redirect portal.
 187  *      This would allow us to "backtrack" on connection failure,
 188  *      as described in draft.
 189  */
 190 static void
 191 login_handle_redirection(struct connection *conn, struct pdu *response)
 192 {
 193         struct iscsi_bhs_login_response *bhslr;
 194         struct keys *response_keys;
 195         const char *target_address;
 196
 197         bhslr = (struct iscsi_bhs_login_response *)response->pdu_bhs;
 198         assert (bhslr->bhslr_status_class == 1);
 199
 200         response_keys = keys_new();
 201         keys_load(response_keys, response);
 202
 203         target_address = keys_find(response_keys, "TargetAddress");
 204         if (target_address == NULL)
 205                 log_errx(1, "received redirection without TargetAddress");
 206         if (target_address[0] == '\0')
 207                 log_errx(1, "received redirection with empty TargetAddress");
 208         if (strlen(target_address) >=
 209             sizeof(conn->conn_conf.isc_target_addr) - 1)
 210                 log_errx(1, "received TargetAddress is too long");
 211
 212         log_debugx("received redirection to \"%s\"", target_address);
 213         kernel_modify(conn, target_address);
 214         keys_delete(response_keys);
 215 }
 216
 217 static struct pdu *
 218 login_receive(struct connection *conn)
 219 {
 220         struct pdu *response;
 221         struct iscsi_bhs_login_response *bhslr;
 222         const char *errorstr;
 223         static bool initial = true;
 224
 225         response = pdu_new(conn);
 226         pdu_receive(response);
 227         if (response->pdu_bhs->bhs_opcode != ISCSI_BHS_OPCODE_LOGIN_RESPONSE) {
 228                 log_errx(1, "protocol error: received invalid opcode 0x%x",
 229                     response->pdu_bhs->bhs_opcode);
 230         }
 231         bhslr = (struct iscsi_bhs_login_response *)response->pdu_bhs;
 232         /*
 233          * XXX: Implement the C flag some day.
 234          */
 235         if ((bhslr->bhslr_flags & BHSLR_FLAGS_CONTINUE) != 0)
 236                 log_errx(1, "received Login PDU with unsupported \"C\" flag");
 237         if (bhslr->bhslr_version_max != 0x00)
 238                 log_errx(1, "received Login PDU with unsupported "
 239                     "Version-max 0x%x", bhslr->bhslr_version_max);
 240         if (bhslr->bhslr_version_active != 0x00)
 241                 log_errx(1, "received Login PDU with unsupported "
 242                     "Version-active 0x%x", bhslr->bhslr_version_active);
 243         if (bhslr->bhslr_status_class == 1) {
 244                 login_handle_redirection(conn, response);
 245                 log_debugx("redirection handled; exiting");
 246                 exit(0);
 247         }
 248         if (bhslr->bhslr_status_class != 0) {
 249                 errorstr = login_target_error_str(bhslr->bhslr_status_class,
 250                     bhslr->bhslr_status_detail);
 251                 fail(conn, errorstr);
 252                 log_errx(1, "target returned error: %s", errorstr);
 253         }
 254         if (initial == false &&
 255             ntohl(bhslr->bhslr_statsn) != conn->conn_statsn + 1) {
 256                 /*
 257                  * It's a warning, not an error, to work around what seems
 258                  * to be bug in NetBSD iSCSI target.
 259                  */
 260                 log_warnx("received Login PDU with wrong StatSN: "
 261                     "is %u, should be %u", ntohl(bhslr->bhslr_statsn),
 262                     conn->conn_statsn + 1);
 263         }
 264         conn->conn_tsih = ntohs(bhslr->bhslr_tsih);
 265         conn->conn_statsn = ntohl(bhslr->bhslr_statsn);
 266
 267         initial = false;
 268
 269         return (response);
 270 }
 271
 272 static struct pdu *
 273 login_new_request(struct connection *conn, int csg)
 274 {
 275         struct pdu *request;
 276         struct iscsi_bhs_login_request *bhslr;
 277         int nsg;
 278
 279         request = pdu_new(conn);
 280         bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs;
 281         bhslr->bhslr_opcode = ISCSI_BHS_OPCODE_LOGIN_REQUEST |
 282             ISCSI_BHS_OPCODE_IMMEDIATE;
 283
 284         bhslr->bhslr_flags = BHSLR_FLAGS_TRANSIT;
 285         switch (csg) {
 286         case BHSLR_STAGE_SECURITY_NEGOTIATION:
 287                 nsg = BHSLR_STAGE_OPERATIONAL_NEGOTIATION;
 288                 break;
 289         case BHSLR_STAGE_OPERATIONAL_NEGOTIATION:
 290                 nsg = BHSLR_STAGE_FULL_FEATURE_PHASE;
 291                 break;
 292         default:
 293                 assert(!"invalid csg");
 294                 log_errx(1, "invalid csg %d", csg);
 295         }
 296         login_set_csg(request, csg);
 297         login_set_nsg(request, nsg);
 298
 299         memcpy(bhslr->bhslr_isid, &conn->conn_isid, sizeof(bhslr->bhslr_isid));
 300         bhslr->bhslr_tsih = htons(conn->conn_tsih);
 301         bhslr->bhslr_initiator_task_tag = 0;
 302         bhslr->bhslr_cmdsn = 0;
 303         bhslr->bhslr_expstatsn = htonl(conn->conn_statsn + 1);
 304
 305         return (request);
 306 }
 307
 308 static int
 309 login_list_prefers(const char *list,
 310     const char *choice1, const char *choice2)
 311 {
 312         char *tofree, *str, *token;
 313
 314         tofree = str = checked_strdup(list);
 315
 316         while ((token = strsep(&str, ",")) != NULL) {
 317                 if (strcmp(token, choice1) == 0) {
 318                         free(tofree);
 319                         return (1);
 320                 }
 321                 if (strcmp(token, choice2) == 0) {
 322                         free(tofree);
 323                         return (2);
 324                 }
 325         }
 326         free(tofree);
 327         return (-1);
 328 }
 329
 330 static void
 331 login_negotiate_key(struct connection *conn, const char *name,
 332     const char *value)
 333 {
 334         struct iscsi_session_limits *isl;
 335         int which, tmp;
 336
 337         isl = &conn->conn_limits;
 338         if (strcmp(name, "TargetAlias") == 0) {
 339                 strlcpy(conn->conn_target_alias, value,
 340                     sizeof(conn->conn_target_alias));
 341         } else if (strcmp(value, "Irrelevant") == 0) {
 342                 /* Ignore. */
 343         } else if (strcmp(name, "iSCSIProtocolLevel") == 0) {
 344                 tmp = strtoul(value, NULL, 10);
 345                 if (tmp < 0 || tmp > 31)
 346                         log_errx(1, "received invalid iSCSIProtocolLevel");
 347                 conn->conn_protocol_level = tmp;
 348         } else if (strcmp(name, "HeaderDigest") == 0) {
 349                 which = login_list_prefers(value, "CRC32C", "None");
 350                 switch (which) {
 351                 case 1:
 352                         log_debugx("target prefers CRC32C "
 353                             "for header digest; we'll use it");
 354                         conn->conn_header_digest = CONN_DIGEST_CRC32C;
 355                         break;
 356                 case 2:
 357                         log_debugx("target prefers not to do "
 358                             "header digest; we'll comply");
 359                         break;
 360                 default:
 361                         log_warnx("target sent unrecognized "
 362                             "HeaderDigest value \"%s\"; will use None", value);
 363                         break;
 364                 }
 365         } else if (strcmp(name, "DataDigest") == 0) {
 366                 which = login_list_prefers(value, "CRC32C", "None");
 367                 switch (which) {
 368                 case 1:
 369                         log_debugx("target prefers CRC32C "
 370                             "for data digest; we'll use it");
 371                         conn->conn_data_digest = CONN_DIGEST_CRC32C;
 372                         break;
 373                 case 2:
 374                         log_debugx("target prefers not to do "
 375                             "data digest; we'll comply");
 376                         break;
 377                 default:
 378                         log_warnx("target sent unrecognized "
 379                             "DataDigest value \"%s\"; will use None", value);
 380                         break;
 381                 }
 382         } else if (strcmp(name, "MaxConnections") == 0) {
 383                 /* Ignore. */
 384         } else if (strcmp(name, "InitialR2T") == 0) {
 385                 if (strcmp(value, "Yes") == 0)
 386                         conn->conn_initial_r2t = true;
 387                 else
 388                         conn->conn_initial_r2t = false;
 389         } else if (strcmp(name, "ImmediateData") == 0) {
 390                 if (strcmp(value, "Yes") == 0)
 391                         conn->conn_immediate_data = true;
 392                 else
 393                         conn->conn_immediate_data = false;
 394         } else if (strcmp(name, "MaxRecvDataSegmentLength") == 0) {
 395                 tmp = strtoul(value, NULL, 10);
 396                 if (tmp <= 0)
 397                         log_errx(1, "received invalid "
 398                             "MaxRecvDataSegmentLength");
 399                 if (tmp > isl->isl_max_send_data_segment_length) {
 400                         log_debugx("capping max_send_data_segment_length "
 401                             "from %d to %d", tmp,
 402                             isl->isl_max_send_data_segment_length);
 403                         tmp = isl->isl_max_send_data_segment_length;
 404                 }
 405                 conn->conn_max_send_data_segment_length = tmp;
 406                 /* We received target's limit, that means it accepted our's. */
 407                 conn->conn_max_recv_data_segment_length =
 408                     isl->isl_max_recv_data_segment_length;
 409         } else if (strcmp(name, "MaxBurstLength") == 0) {
 410                 tmp = strtoul(value, NULL, 10);
 411                 if (tmp <= 0)
 412                         log_errx(1, "received invalid MaxBurstLength");
 413                 if (tmp > isl->isl_max_burst_length) {
 414                         log_debugx("capping MaxBurstLength "
 415                             "from %d to %d", tmp, isl->isl_max_burst_length);
 416                         tmp = isl->isl_max_burst_length;
 417                 }
 418                 conn->conn_max_burst_length = tmp;
 419         } else if (strcmp(name, "FirstBurstLength") == 0) {
 420                 tmp = strtoul(value, NULL, 10);
 421                 if (tmp <= 0)
 422                         log_errx(1, "received invalid FirstBurstLength");
 423                 if (tmp > isl->isl_first_burst_length) {
 424                         log_debugx("capping FirstBurstLength "
 425                             "from %d to %d", tmp, isl->isl_first_burst_length);
 426                         tmp = isl->isl_first_burst_length;
 427                 }
 428                 conn->conn_first_burst_length = tmp;
 429         } else if (strcmp(name, "DefaultTime2Wait") == 0) {
 430                 /* Ignore */
 431         } else if (strcmp(name, "DefaultTime2Retain") == 0) {
 432                 /* Ignore */
 433         } else if (strcmp(name, "MaxOutstandingR2T") == 0) {
 434                 /* Ignore */
 435         } else if (strcmp(name, "DataPDUInOrder") == 0) {
 436                 /* Ignore */
 437         } else if (strcmp(name, "DataSequenceInOrder") == 0) {
 438                 /* Ignore */
 439         } else if (strcmp(name, "ErrorRecoveryLevel") == 0) {
 440                 /* Ignore */
 441         } else if (strcmp(name, "OFMarker") == 0) {
 442                 /* Ignore */
 443         } else if (strcmp(name, "IFMarker") == 0) {
 444                 /* Ignore */
 445         } else if (strcmp(name, "RDMAExtensions") == 0) {
 446                 if (conn->conn_conf.isc_iser == 1 &&
 447                     strcmp(value, "Yes") != 0) {
 448                         log_errx(1, "received unsupported RDMAExtensions");
 449                 }
 450         } else if (strcmp(name, "InitiatorRecvDataSegmentLength") == 0) {
 451                 tmp = strtoul(value, NULL, 10);
 452                 if (tmp <= 0)
 453                         log_errx(1, "received invalid "
 454                             "InitiatorRecvDataSegmentLength");
 455                 if ((int)tmp > isl->isl_max_recv_data_segment_length) {
 456                         log_debugx("capping InitiatorRecvDataSegmentLength "
 457                             "from %d to %d", tmp,
 458                             isl->isl_max_recv_data_segment_length);
 459                         tmp = isl->isl_max_recv_data_segment_length;
 460                 }
 461                 conn->conn_max_recv_data_segment_length = tmp;
 462         } else if (strcmp(name, "TargetPortalGroupTag") == 0) {
 463                 /* Ignore */
 464         } else if (strcmp(name, "TargetRecvDataSegmentLength") == 0) {
 465                 tmp = strtoul(value, NULL, 10);
 466                 if (tmp <= 0) {
 467                         log_errx(1,
 468                             "received invalid TargetRecvDataSegmentLength");
 469                 }
 470                 if (tmp > isl->isl_max_send_data_segment_length) {
 471                         log_debugx("capping TargetRecvDataSegmentLength "
 472                             "from %d to %d", tmp,
 473                             isl->isl_max_send_data_segment_length);
 474                         tmp = isl->isl_max_send_data_segment_length;
 475                 }
 476                 conn->conn_max_send_data_segment_length = tmp;
 477         } else {
 478                 log_debugx("unknown key \"%s\"; ignoring",  name);
 479         }
 480 }
 481
 482 static void
 483 login_negotiate(struct connection *conn)
 484 {
 485         struct pdu *request, *response;
 486         struct keys *request_keys, *response_keys;
 487         struct iscsi_bhs_login_response *bhslr;
 488         int i, nrequests = 0;
 489         struct iscsi_session_limits *isl;
 490
 491         log_debugx("beginning operational parameter negotiation");
 492         request = login_new_request(conn, BHSLR_STAGE_OPERATIONAL_NEGOTIATION);
 493         request_keys = keys_new();
 494
 495         isl = &conn->conn_limits;
 496         log_debugx("Limits for offload \"%s\" are "
 497             "MaxRecvDataSegment=%d, max_send_dsl=%d, "
 498             "MaxBurstLength=%d, FirstBurstLength=%d",
 499             conn->conn_conf.isc_offload, isl->isl_max_recv_data_segment_length,
 500             isl->isl_max_send_data_segment_length, isl->isl_max_burst_length,
 501             isl->isl_first_burst_length);
 502
 503         /*
 504          * The following keys are irrelevant for discovery sessions.
 505          */
 506         if (conn->conn_conf.isc_discovery == 0) {
 507                 keys_add(request_keys, "iSCSIProtocolLevel", "2");
 508                 if (conn->conn_conf.isc_header_digest != 0)
 509                         keys_add(request_keys, "HeaderDigest", "CRC32C");
 510                 else
 511                         keys_add(request_keys, "HeaderDigest", "None");
 512                 if (conn->conn_conf.isc_data_digest != 0)
 513                         keys_add(request_keys, "DataDigest", "CRC32C");
 514                 else
 515                         keys_add(request_keys, "DataDigest", "None");
 516
 517                 keys_add(request_keys, "ImmediateData", "Yes");
 518                 keys_add_int(request_keys, "MaxBurstLength",
 519                     isl->isl_max_burst_length);
 520                 keys_add_int(request_keys, "FirstBurstLength",
 521                     isl->isl_first_burst_length);
 522                 keys_add(request_keys, "InitialR2T", "Yes");
 523                 keys_add(request_keys, "MaxOutstandingR2T", "1");
 524                 if (conn->conn_conf.isc_iser == 1) {
 525                         keys_add_int(request_keys, "InitiatorRecvDataSegmentLength",
 526                             isl->isl_max_recv_data_segment_length);
 527                         keys_add_int(request_keys, "TargetRecvDataSegmentLength",
 528                             isl->isl_max_send_data_segment_length);
 529                         keys_add(request_keys, "RDMAExtensions", "Yes");
 530                 } else {
 531                         keys_add_int(request_keys, "MaxRecvDataSegmentLength",
 532                             isl->isl_max_recv_data_segment_length);
 533                 }
 534         } else {
 535                 keys_add(request_keys, "HeaderDigest", "None");
 536                 keys_add(request_keys, "DataDigest", "None");
 537                 keys_add_int(request_keys, "MaxRecvDataSegmentLength",
 538                     isl->isl_max_recv_data_segment_length);
 539         }
 540
 541         keys_add(request_keys, "DefaultTime2Wait", "0");
 542         keys_add(request_keys, "DefaultTime2Retain", "0");
 543         keys_add(request_keys, "ErrorRecoveryLevel", "0");
 544         keys_save(request_keys, request);
 545         keys_delete(request_keys);
 546         request_keys = NULL;
 547         pdu_send(request);
 548         pdu_delete(request);
 549         request = NULL;
 550
 551         response = login_receive(conn);
 552         response_keys = keys_new();
 553         keys_load(response_keys, response);
 554         for (i = 0; i < KEYS_MAX; i++) {
 555                 if (response_keys->keys_names[i] == NULL)
 556                         break;
 557
 558                 login_negotiate_key(conn,
 559                     response_keys->keys_names[i], response_keys->keys_values[i]);
 560         }
 561
 562         keys_delete(response_keys);
 563         response_keys = NULL;
 564
 565         for (;;) {
 566                 bhslr = (struct iscsi_bhs_login_response *)response->pdu_bhs;
 567                 if ((bhslr->bhslr_flags & BHSLR_FLAGS_TRANSIT) != 0)
 568                         break;
 569
 570                 nrequests++;
 571                 if (nrequests > 5) {
 572                         log_warnx("received login response "
 573                             "without the \"T\" flag too many times; giving up");
 574                         break;
 575                 }
 576
 577                 log_debugx("received login response "
 578                     "without the \"T\" flag; sending another request");
 579
 580                 pdu_delete(response);
 581
 582                 request = login_new_request(conn,
 583                     BHSLR_STAGE_OPERATIONAL_NEGOTIATION);
 584                 pdu_send(request);
 585                 pdu_delete(request);
 586
 587                 response = login_receive(conn);
 588         }
 589
 590         if (login_nsg(response) != BHSLR_STAGE_FULL_FEATURE_PHASE)
 591                 log_warnx("received final login response with wrong NSG 0x%x",
 592                     login_nsg(response));
 593         pdu_delete(response);
 594
 595         log_debugx("operational parameter negotiation done; "
 596             "transitioning to Full Feature phase");
 597 }
 598
 599 static void
 600 login_send_chap_a(struct connection *conn)
 601 {
 602         struct pdu *request;
 603         struct keys *request_keys;
 604
 605         request = login_new_request(conn, BHSLR_STAGE_SECURITY_NEGOTIATION);
 606         request_keys = keys_new();
 607         keys_add(request_keys, "CHAP_A", "5");
 608         keys_save(request_keys, request);
 609         keys_delete(request_keys);
 610         pdu_send(request);
 611         pdu_delete(request);
 612 }
 613
 614 static void
 615 login_send_chap_r(struct pdu *response)
 616 {
 617         struct connection *conn;
 618         struct pdu *request;
 619         struct keys *request_keys, *response_keys;
 620         struct rchap *rchap;
 621         const char *chap_a, *chap_c, *chap_i;
 622         char *chap_r;
 623         int error;
 624         char *mutual_chap_c, *mutual_chap_i;
 625
 626         /*
 627          * As in the rest of the initiator, 'request' means
 628          * 'initiator -> target', and 'response' means 'target -> initiator',
 629          *
 630          * So, here the 'response' from the target is the packet that contains
 631          * CHAP challenge; our CHAP response goes into 'request'.
 632          */
 633
 634         conn = response->pdu_connection;
 635
 636         response_keys = keys_new();
 637         keys_load(response_keys, response);
 638
 639         /*
 640          * First, compute the response.
 641          */
 642         chap_a = keys_find(response_keys, "CHAP_A");
 643         if (chap_a == NULL)
 644                 log_errx(1, "received CHAP packet without CHAP_A");
 645         chap_c = keys_find(response_keys, "CHAP_C");
 646         if (chap_c == NULL)
 647                 log_errx(1, "received CHAP packet without CHAP_C");
 648         chap_i = keys_find(response_keys, "CHAP_I");
 649         if (chap_i == NULL)
 650                 log_errx(1, "received CHAP packet without CHAP_I");
 651
 652         if (strcmp(chap_a, "5") != 0) {
 653                 log_errx(1, "received CHAP packet "
 654                     "with unsupported CHAP_A \"%s\"", chap_a);
 655         }
 656
 657         rchap = rchap_new(conn->conn_conf.isc_secret);
 658         error = rchap_receive(rchap, chap_i, chap_c);
 659         if (error != 0) {
 660                 log_errx(1, "received CHAP packet "
 661                     "with malformed CHAP_I or CHAP_C");
 662         }
 663         chap_r = rchap_get_response(rchap);
 664         rchap_delete(rchap);
 665
 666         keys_delete(response_keys);
 667
 668         request = login_new_request(conn, BHSLR_STAGE_SECURITY_NEGOTIATION);
 669         request_keys = keys_new();
 670         keys_add(request_keys, "CHAP_N", conn->conn_conf.isc_user);
 671         keys_add(request_keys, "CHAP_R", chap_r);
 672         free(chap_r);
 673
 674         /*
 675          * If we want mutual authentication, we're expected to send
 676          * our CHAP_I/CHAP_C now.
 677          */
 678         if (conn->conn_conf.isc_mutual_user[0] != '\0') {
 679                 log_debugx("requesting mutual authentication; "
 680                     "binary challenge size is %zd bytes",
 681                     sizeof(conn->conn_mutual_chap->chap_challenge));
 682
 683                 assert(conn->conn_mutual_chap == NULL);
 684                 conn->conn_mutual_chap = chap_new();
 685                 mutual_chap_i = chap_get_id(conn->conn_mutual_chap);
 686                 mutual_chap_c = chap_get_challenge(conn->conn_mutual_chap);
 687                 keys_add(request_keys, "CHAP_I", mutual_chap_i);
 688                 keys_add(request_keys, "CHAP_C", mutual_chap_c);
 689                 free(mutual_chap_i);
 690                 free(mutual_chap_c);
 691         }
 692
 693         keys_save(request_keys, request);
 694         keys_delete(request_keys);
 695         pdu_send(request);
 696         pdu_delete(request);
 697 }
 698
 699 static void
 700 login_verify_mutual(const struct pdu *response)
 701 {
 702         struct connection *conn;
 703         struct keys *response_keys;
 704         const char *chap_n, *chap_r;
 705         int error;
 706
 707         conn = response->pdu_connection;
 708
 709         response_keys = keys_new();
 710         keys_load(response_keys, response);
 711
 712         chap_n = keys_find(response_keys, "CHAP_N");
 713         if (chap_n == NULL)
 714                 log_errx(1, "received CHAP Response PDU without CHAP_N");
 715         chap_r = keys_find(response_keys, "CHAP_R");
 716         if (chap_r == NULL)
 717                 log_errx(1, "received CHAP Response PDU without CHAP_R");
 718
 719         error = chap_receive(conn->conn_mutual_chap, chap_r);
 720         if (error != 0)
 721                 log_errx(1, "received CHAP Response PDU with invalid CHAP_R");
 722
 723         if (strcmp(chap_n, conn->conn_conf.isc_mutual_user) != 0) {
 724                 fail(conn, "Mutual CHAP failed");
 725                 log_errx(1, "mutual CHAP authentication failed: wrong user");
 726         }
 727
 728         error = chap_authenticate(conn->conn_mutual_chap,
 729             conn->conn_conf.isc_mutual_secret);
 730         if (error != 0) {
 731                 fail(conn, "Mutual CHAP failed");
 732                 log_errx(1, "mutual CHAP authentication failed: wrong secret");
 733         }
 734
 735         keys_delete(response_keys);
 736         chap_delete(conn->conn_mutual_chap);
 737         conn->conn_mutual_chap = NULL;
 738
 739         log_debugx("mutual CHAP authentication succeeded");
 740 }
 741
 742 static void
 743 login_chap(struct connection *conn)
 744 {
 745         struct pdu *response;
 746
 747         log_debugx("beginning CHAP authentication; sending CHAP_A");
 748         login_send_chap_a(conn);
 749
 750         log_debugx("waiting for CHAP_A/CHAP_C/CHAP_I");
 751         response = login_receive(conn);
 752
 753         log_debugx("sending CHAP_N/CHAP_R");
 754         login_send_chap_r(response);
 755         pdu_delete(response);
 756
 757         /*
 758          * XXX: Make sure this is not susceptible to MITM.
 759          */
 760
 761         log_debugx("waiting for CHAP result");
 762         response = login_receive(conn);
 763         if (conn->conn_conf.isc_mutual_user[0] != '\0')
 764                 login_verify_mutual(response);
 765         pdu_delete(response);
 766
 767         log_debugx("CHAP authentication done");
 768 }
 769
 770 void
 771 login(struct connection *conn)
 772 {
 773         struct pdu *request, *response;
 774         struct keys *request_keys, *response_keys;
 775         struct iscsi_bhs_login_response *bhslr2;
 776         const char *auth_method;
 777         int i;
 778
 779         log_debugx("beginning Login phase; sending Login PDU");
 780         request = login_new_request(conn, BHSLR_STAGE_SECURITY_NEGOTIATION);
 781         request_keys = keys_new();
 782         if (conn->conn_conf.isc_mutual_user[0] != '\0') {
 783                 keys_add(request_keys, "AuthMethod", "CHAP");
 784         } else if (conn->conn_conf.isc_user[0] != '\0') {
 785                 /*
 786                  * Give target a chance to skip authentication if it
 787                  * doesn't feel like it.
 788                  *
 789                  * None is first, CHAP second; this is to work around
 790                  * what seems to be LIO (Linux target) bug: otherwise,
 791                  * if target is configured with no authentication,
 792                  * and we are configured to authenticate, the target
 793                  * will erroneously respond with AuthMethod=CHAP
 794                  * instead of AuthMethod=None, and will subsequently
 795                  * fail the connection.  This usually happens with
 796                  * Discovery sessions, which default to no authentication.
 797                  */
 798                 keys_add(request_keys, "AuthMethod", "None,CHAP");
 799         } else {
 800                 keys_add(request_keys, "AuthMethod", "None");
 801         }
 802         keys_add(request_keys, "InitiatorName",
 803             conn->conn_conf.isc_initiator);
 804         if (conn->conn_conf.isc_initiator_alias[0] != '\0') {
 805                 keys_add(request_keys, "InitiatorAlias",
 806                     conn->conn_conf.isc_initiator_alias);
 807         }
 808         if (conn->conn_conf.isc_discovery == 0) {
 809                 keys_add(request_keys, "SessionType", "Normal");
 810                 keys_add(request_keys,
 811                     "TargetName", conn->conn_conf.isc_target);
 812         } else {
 813                 keys_add(request_keys, "SessionType", "Discovery");
 814         }
 815         keys_save(request_keys, request);
 816         keys_delete(request_keys);
 817         pdu_send(request);
 818         pdu_delete(request);
 819
 820         response = login_receive(conn);
 821
 822         response_keys = keys_new();
 823         keys_load(response_keys, response);
 824
 825         for (i = 0; i < KEYS_MAX; i++) {
 826                 if (response_keys->keys_names[i] == NULL)
 827                         break;
 828
 829                 /*
 830                  * Not interested in AuthMethod at this point; we only need
 831                  * to parse things such as TargetAlias.
 832                  *
 833                  * XXX: This is somewhat ugly.  We should have a way to apply
 834                  *      all the keys to the session and use that by default
 835                  *      instead of discarding them.
 836                  */
 837                 if (strcmp(response_keys->keys_names[i], "AuthMethod") == 0)
 838                         continue;
 839
 840                 login_negotiate_key(conn,
 841                     response_keys->keys_names[i], response_keys->keys_values[i]);
 842         }
 843
 844         bhslr2 = (struct iscsi_bhs_login_response *)response->pdu_bhs;
 845         if ((bhslr2->bhslr_flags & BHSLR_FLAGS_TRANSIT) != 0 &&
 846             login_nsg(response) == BHSLR_STAGE_OPERATIONAL_NEGOTIATION) {
 847                 if (conn->conn_conf.isc_mutual_user[0] != '\0') {
 848                         log_errx(1, "target requested transition "
 849                             "to operational parameter negotiation, "
 850                             "but we require mutual CHAP");
 851                 }
 852
 853                 log_debugx("target requested transition "
 854                     "to operational parameter negotiation");
 855                 keys_delete(response_keys);
 856                 pdu_delete(response);
 857                 login_negotiate(conn);
 858                 return;
 859         }
 860
 861         auth_method = keys_find(response_keys, "AuthMethod");
 862         if (auth_method == NULL)
 863                 log_errx(1, "received response without AuthMethod");
 864         if (strcmp(auth_method, "None") == 0) {
 865                 if (conn->conn_conf.isc_mutual_user[0] != '\0') {
 866                         log_errx(1, "target does not require authantication, "
 867                             "but we require mutual CHAP");
 868                 }
 869
 870                 log_debugx("target does not require authentication");
 871                 keys_delete(response_keys);
 872                 pdu_delete(response);
 873                 login_negotiate(conn);
 874                 return;
 875         }
 876
 877         if (strcmp(auth_method, "CHAP") != 0) {
 878                 fail(conn, "Unsupported AuthMethod");
 879                 log_errx(1, "received response "
 880                     "with unsupported AuthMethod \"%s\"", auth_method);
 881         }
 882
 883         if (conn->conn_conf.isc_user[0] == '\0' ||
 884             conn->conn_conf.isc_secret[0] == '\0') {
 885                 fail(conn, "Authentication required");
 886                 log_errx(1, "target requests CHAP authentication, but we don't "
 887                     "have user and secret");
 888         }
 889
 890         keys_delete(response_keys);
 891         response_keys = NULL;
 892         pdu_delete(response);
 893         response = NULL;
 894
 895         login_chap(conn);
 896         login_negotiate(conn);
 897 }