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_addr));
 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, "iSCSIProtocolLevel") == 0) {
 345                 tmp = strtoul(value, NULL, 10);
 346                 if (tmp < 0 || tmp > 31)
 347                         log_errx(1, "received invalid iSCSIProtocolLevel");
 348                 conn->conn_protocol_level = tmp;
 349         } else if (strcmp(name, "HeaderDigest") == 0) {
 350                 which = login_list_prefers(value, "CRC32C", "None");
 351                 switch (which) {
 352                 case 1:
 353                         log_debugx("target prefers CRC32C "
 354                             "for header digest; we'll use it");
 355                         conn->conn_header_digest = CONN_DIGEST_CRC32C;
 356                         break;
 357                 case 2:
 358                         log_debugx("target prefers not to do "
 359                             "header digest; we'll comply");
 360                         break;
 361                 default:
 362                         log_warnx("target sent unrecognized "
 363                             "HeaderDigest value \"%s\"; will use None", value);
 364                         break;
 365                 }
 366         } else if (strcmp(name, "DataDigest") == 0) {
 367                 which = login_list_prefers(value, "CRC32C", "None");
 368                 switch (which) {
 369                 case 1:
 370                         log_debugx("target prefers CRC32C "
 371                             "for data digest; we'll use it");
 372                         conn->conn_data_digest = CONN_DIGEST_CRC32C;
 373                         break;
 374                 case 2:
 375                         log_debugx("target prefers not to do "
 376                             "data digest; we'll comply");
 377                         break;
 378                 default:
 379                         log_warnx("target sent unrecognized "
 380                             "DataDigest value \"%s\"; will use None", value);
 381                         break;
 382                 }
 383         } else if (strcmp(name, "MaxConnections") == 0) {
 384                 /* Ignore. */
 385         } else if (strcmp(name, "InitialR2T") == 0) {
 386                 if (strcmp(value, "Yes") == 0)
 387                         conn->conn_initial_r2t = true;
 388                 else
 389                         conn->conn_initial_r2t = false;
 390         } else if (strcmp(name, "ImmediateData") == 0) {
 391                 if (strcmp(value, "Yes") == 0)
 392                         conn->conn_immediate_data = true;
 393                 else
 394                         conn->conn_immediate_data = false;
 395         } else if (strcmp(name, "MaxRecvDataSegmentLength") == 0) {
 396                 tmp = strtoul(value, NULL, 10);
 397                 if (tmp <= 0)
 398                         log_errx(1, "received invalid "
 399                             "MaxRecvDataSegmentLength");
 400                 if (tmp > isl->isl_max_send_data_segment_length) {
 401                         log_debugx("capping max_send_data_segment_length "
 402                             "from %d to %d", tmp,
 403                             isl->isl_max_send_data_segment_length);
 404                         tmp = isl->isl_max_send_data_segment_length;
 405                 }
 406                 conn->conn_max_send_data_segment_length = tmp;
 407                 /* We received target's limit, that means it accepted our's. */
 408                 conn->conn_max_recv_data_segment_length =
 409                     isl->isl_max_recv_data_segment_length;
 410         } else if (strcmp(name, "MaxBurstLength") == 0) {
 411                 tmp = strtoul(value, NULL, 10);
 412                 if (tmp <= 0)
 413                         log_errx(1, "received invalid MaxBurstLength");
 414                 if (tmp > isl->isl_max_burst_length) {
 415                         log_debugx("capping MaxBurstLength "
 416                             "from %d to %d", tmp, isl->isl_max_burst_length);
 417                         tmp = isl->isl_max_burst_length;
 418                 }
 419                 conn->conn_max_burst_length = tmp;
 420         } else if (strcmp(name, "FirstBurstLength") == 0) {
 421                 tmp = strtoul(value, NULL, 10);
 422                 if (tmp <= 0)
 423                         log_errx(1, "received invalid FirstBurstLength");
 424                 if (tmp > isl->isl_first_burst_length) {
 425                         log_debugx("capping FirstBurstLength "
 426                             "from %d to %d", tmp, isl->isl_first_burst_length);
 427                         tmp = isl->isl_first_burst_length;
 428                 }
 429                 conn->conn_first_burst_length = tmp;
 430         } else if (strcmp(name, "DefaultTime2Wait") == 0) {
 431                 /* Ignore */
 432         } else if (strcmp(name, "DefaultTime2Retain") == 0) {
 433                 /* Ignore */
 434         } else if (strcmp(name, "MaxOutstandingR2T") == 0) {
 435                 /* Ignore */
 436         } else if (strcmp(name, "DataPDUInOrder") == 0) {
 437                 /* Ignore */
 438         } else if (strcmp(name, "DataSequenceInOrder") == 0) {
 439                 /* Ignore */
 440         } else if (strcmp(name, "ErrorRecoveryLevel") == 0) {
 441                 /* Ignore */
 442         } else if (strcmp(name, "OFMarker") == 0) {
 443                 /* Ignore */
 444         } else if (strcmp(name, "IFMarker") == 0) {
 445                 /* Ignore */
 446         } else if (strcmp(name, "RDMAExtensions") == 0) {
 447                 if (conn->conn_conf.isc_iser == 1 &&
 448                     strcmp(value, "Yes") != 0) {
 449                         log_errx(1, "received unsupported RDMAExtensions");
 450                 }
 451         } else if (strcmp(name, "InitiatorRecvDataSegmentLength") == 0) {
 452                 tmp = strtoul(value, NULL, 10);
 453                 if (tmp <= 0)
 454                         log_errx(1, "received invalid "
 455                             "InitiatorRecvDataSegmentLength");
 456                 if ((int)tmp > isl->isl_max_recv_data_segment_length) {
 457                         log_debugx("capping InitiatorRecvDataSegmentLength "
 458                             "from %d to %d", tmp,
 459                             isl->isl_max_recv_data_segment_length);
 460                         tmp = isl->isl_max_recv_data_segment_length;
 461                 }
 462                 conn->conn_max_recv_data_segment_length = tmp;
 463         } else if (strcmp(name, "TargetPortalGroupTag") == 0) {
 464                 /* Ignore */
 465         } else if (strcmp(name, "TargetRecvDataSegmentLength") == 0) {
 466                 tmp = strtoul(value, NULL, 10);
 467                 if (tmp <= 0) {
 468                         log_errx(1,
 469                             "received invalid TargetRecvDataSegmentLength");
 470                 }
 471                 if (tmp > isl->isl_max_send_data_segment_length) {
 472                         log_debugx("capping TargetRecvDataSegmentLength "
 473                             "from %d to %d", tmp,
 474                             isl->isl_max_send_data_segment_length);
 475                         tmp = isl->isl_max_send_data_segment_length;
 476                 }
 477                 conn->conn_max_send_data_segment_length = tmp;
 478         } else {
 479                 log_debugx("unknown key \"%s\"; ignoring",  name);
 480         }
 481 }
 482
 483 static void
 484 login_negotiate(struct connection *conn)
 485 {
 486         struct pdu *request, *response;
 487         struct keys *request_keys, *response_keys;
 488         struct iscsi_bhs_login_response *bhslr;
 489         int i, nrequests = 0;
 490         struct iscsi_session_limits *isl;
 491
 492         log_debugx("beginning operational parameter negotiation");
 493         request = login_new_request(conn, BHSLR_STAGE_OPERATIONAL_NEGOTIATION);
 494         request_keys = keys_new();
 495
 496         isl = &conn->conn_limits;
 497         log_debugx("Limits for offload \"%s\" are "
 498             "MaxRecvDataSegment=%d, max_send_dsl=%d, "
 499             "MaxBurstLength=%d, FirstBurstLength=%d",
 500             conn->conn_conf.isc_offload, isl->isl_max_recv_data_segment_length,
 501             isl->isl_max_send_data_segment_length, isl->isl_max_burst_length,
 502             isl->isl_first_burst_length);
 503
 504         /*
 505          * The following keys are irrelevant for discovery sessions.
 506          */
 507         if (conn->conn_conf.isc_discovery == 0) {
 508                 keys_add(request_keys, "iSCSIProtocolLevel", "2");
 509                 if (conn->conn_conf.isc_header_digest != 0)
 510                         keys_add(request_keys, "HeaderDigest", "CRC32C");
 511                 else
 512                         keys_add(request_keys, "HeaderDigest", "None");
 513                 if (conn->conn_conf.isc_data_digest != 0)
 514                         keys_add(request_keys, "DataDigest", "CRC32C");
 515                 else
 516                         keys_add(request_keys, "DataDigest", "None");
 517
 518                 keys_add(request_keys, "ImmediateData", "Yes");
 519                 keys_add_int(request_keys, "MaxBurstLength",
 520                     isl->isl_max_burst_length);
 521                 keys_add_int(request_keys, "FirstBurstLength",
 522                     isl->isl_first_burst_length);
 523                 keys_add(request_keys, "InitialR2T", "Yes");
 524                 keys_add(request_keys, "MaxOutstandingR2T", "1");
 525                 if (conn->conn_conf.isc_iser == 1) {
 526                         keys_add_int(request_keys, "InitiatorRecvDataSegmentLength",
 527                             isl->isl_max_recv_data_segment_length);
 528                         keys_add_int(request_keys, "TargetRecvDataSegmentLength",
 529                             isl->isl_max_send_data_segment_length);
 530                         keys_add(request_keys, "RDMAExtensions", "Yes");
 531                 } else {
 532                         keys_add_int(request_keys, "MaxRecvDataSegmentLength",
 533                             isl->isl_max_recv_data_segment_length);
 534                 }
 535         } else {
 536                 keys_add(request_keys, "HeaderDigest", "None");
 537                 keys_add(request_keys, "DataDigest", "None");
 538                 keys_add_int(request_keys, "MaxRecvDataSegmentLength",
 539                     isl->isl_max_recv_data_segment_length);
 540         }
 541
 542         keys_add(request_keys, "DefaultTime2Wait", "0");
 543         keys_add(request_keys, "DefaultTime2Retain", "0");
 544         keys_add(request_keys, "ErrorRecoveryLevel", "0");
 545         keys_save(request_keys, request);
 546         keys_delete(request_keys);
 547         request_keys = NULL;
 548         pdu_send(request);
 549         pdu_delete(request);
 550         request = NULL;
 551
 552         response = login_receive(conn);
 553         response_keys = keys_new();
 554         keys_load(response_keys, response);
 555         for (i = 0; i < KEYS_MAX; i++) {
 556                 if (response_keys->keys_names[i] == NULL)
 557                         break;
 558
 559                 login_negotiate_key(conn,
 560                     response_keys->keys_names[i], response_keys->keys_values[i]);
 561         }
 562
 563         keys_delete(response_keys);
 564         response_keys = NULL;
 565
 566         for (;;) {
 567                 bhslr = (struct iscsi_bhs_login_response *)response->pdu_bhs;
 568                 if ((bhslr->bhslr_flags & BHSLR_FLAGS_TRANSIT) != 0)
 569                         break;
 570
 571                 nrequests++;
 572                 if (nrequests > 5) {
 573                         log_warnx("received login response "
 574                             "without the \"T\" flag too many times; giving up");
 575                         break;
 576                 }
 577
 578                 log_debugx("received login response "
 579                     "without the \"T\" flag; sending another request");
 580
 581                 pdu_delete(response);
 582
 583                 request = login_new_request(conn,
 584                     BHSLR_STAGE_OPERATIONAL_NEGOTIATION);
 585                 pdu_send(request);
 586                 pdu_delete(request);
 587
 588                 response = login_receive(conn);
 589         }
 590
 591         if (login_nsg(response) != BHSLR_STAGE_FULL_FEATURE_PHASE)
 592                 log_warnx("received final login response with wrong NSG 0x%x",
 593                     login_nsg(response));
 594         pdu_delete(response);
 595
 596         log_debugx("operational parameter negotiation done; "
 597             "transitioning to Full Feature phase");
 598 }
 599
 600 static void
 601 login_send_chap_a(struct connection *conn)
 602 {
 603         struct pdu *request;
 604         struct keys *request_keys;
 605
 606         request = login_new_request(conn, BHSLR_STAGE_SECURITY_NEGOTIATION);
 607         request_keys = keys_new();
 608         keys_add(request_keys, "CHAP_A", "5");
 609         keys_save(request_keys, request);
 610         keys_delete(request_keys);
 611         pdu_send(request);
 612         pdu_delete(request);
 613 }
 614
 615 static void
 616 login_send_chap_r(struct pdu *response)
 617 {
 618         struct connection *conn;
 619         struct pdu *request;
 620         struct keys *request_keys, *response_keys;
 621         struct rchap *rchap;
 622         const char *chap_a, *chap_c, *chap_i;
 623         char *chap_r;
 624         int error;
 625         char *mutual_chap_c, *mutual_chap_i;
 626
 627         /*
 628          * As in the rest of the initiator, 'request' means
 629          * 'initiator -> target', and 'response' means 'target -> initiator',
 630          *
 631          * So, here the 'response' from the target is the packet that contains
 632          * CHAP challenge; our CHAP response goes into 'request'.
 633          */
 634
 635         conn = response->pdu_connection;
 636
 637         response_keys = keys_new();
 638         keys_load(response_keys, response);
 639
 640         /*
 641          * First, compute the response.
 642          */
 643         chap_a = keys_find(response_keys, "CHAP_A");
 644         if (chap_a == NULL)
 645                 log_errx(1, "received CHAP packet without CHAP_A");
 646         chap_c = keys_find(response_keys, "CHAP_C");
 647         if (chap_c == NULL)
 648                 log_errx(1, "received CHAP packet without CHAP_C");
 649         chap_i = keys_find(response_keys, "CHAP_I");
 650         if (chap_i == NULL)
 651                 log_errx(1, "received CHAP packet without CHAP_I");
 652
 653         if (strcmp(chap_a, "5") != 0) {
 654                 log_errx(1, "received CHAP packet "
 655                     "with unsupported CHAP_A \"%s\"", chap_a);
 656         }
 657
 658         rchap = rchap_new(conn->conn_conf.isc_secret);
 659         error = rchap_receive(rchap, chap_i, chap_c);
 660         if (error != 0) {
 661                 log_errx(1, "received CHAP packet "
 662                     "with malformed CHAP_I or CHAP_C");
 663         }
 664         chap_r = rchap_get_response(rchap);
 665         rchap_delete(rchap);
 666
 667         keys_delete(response_keys);
 668
 669         request = login_new_request(conn, BHSLR_STAGE_SECURITY_NEGOTIATION);
 670         request_keys = keys_new();
 671         keys_add(request_keys, "CHAP_N", conn->conn_conf.isc_user);
 672         keys_add(request_keys, "CHAP_R", chap_r);
 673         free(chap_r);
 674
 675         /*
 676          * If we want mutual authentication, we're expected to send
 677          * our CHAP_I/CHAP_C now.
 678          */
 679         if (conn->conn_conf.isc_mutual_user[0] != '\0') {
 680                 log_debugx("requesting mutual authentication; "
 681                     "binary challenge size is %zd bytes",
 682                     sizeof(conn->conn_mutual_chap->chap_challenge));
 683
 684                 assert(conn->conn_mutual_chap == NULL);
 685                 conn->conn_mutual_chap = chap_new();
 686                 mutual_chap_i = chap_get_id(conn->conn_mutual_chap);
 687                 mutual_chap_c = chap_get_challenge(conn->conn_mutual_chap);
 688                 keys_add(request_keys, "CHAP_I", mutual_chap_i);
 689                 keys_add(request_keys, "CHAP_C", mutual_chap_c);
 690                 free(mutual_chap_i);
 691                 free(mutual_chap_c);
 692         }
 693
 694         keys_save(request_keys, request);
 695         keys_delete(request_keys);
 696         pdu_send(request);
 697         pdu_delete(request);
 698 }
 699
 700 static void
 701 login_verify_mutual(const struct pdu *response)
 702 {
 703         struct connection *conn;
 704         struct keys *response_keys;
 705         const char *chap_n, *chap_r;
 706         int error;
 707
 708         conn = response->pdu_connection;
 709
 710         response_keys = keys_new();
 711         keys_load(response_keys, response);
 712
 713         chap_n = keys_find(response_keys, "CHAP_N");
 714         if (chap_n == NULL)
 715                 log_errx(1, "received CHAP Response PDU without CHAP_N");
 716         chap_r = keys_find(response_keys, "CHAP_R");
 717         if (chap_r == NULL)
 718                 log_errx(1, "received CHAP Response PDU without CHAP_R");
 719
 720         error = chap_receive(conn->conn_mutual_chap, chap_r);
 721         if (error != 0)
 722                 log_errx(1, "received CHAP Response PDU with invalid CHAP_R");
 723
 724         if (strcmp(chap_n, conn->conn_conf.isc_mutual_user) != 0) {
 725                 fail(conn, "Mutual CHAP failed");
 726                 log_errx(1, "mutual CHAP authentication failed: wrong user");
 727         }
 728
 729         error = chap_authenticate(conn->conn_mutual_chap,
 730             conn->conn_conf.isc_mutual_secret);
 731         if (error != 0) {
 732                 fail(conn, "Mutual CHAP failed");
 733                 log_errx(1, "mutual CHAP authentication failed: wrong secret");
 734         }
 735
 736         keys_delete(response_keys);
 737         chap_delete(conn->conn_mutual_chap);
 738         conn->conn_mutual_chap = NULL;
 739
 740         log_debugx("mutual CHAP authentication succeeded");
 741 }
 742
 743 static void
 744 login_chap(struct connection *conn)
 745 {
 746         struct pdu *response;
 747
 748         log_debugx("beginning CHAP authentication; sending CHAP_A");
 749         login_send_chap_a(conn);
 750
 751         log_debugx("waiting for CHAP_A/CHAP_C/CHAP_I");
 752         response = login_receive(conn);
 753
 754         log_debugx("sending CHAP_N/CHAP_R");
 755         login_send_chap_r(response);
 756         pdu_delete(response);
 757
 758         /*
 759          * XXX: Make sure this is not susceptible to MITM.
 760          */
 761
 762         log_debugx("waiting for CHAP result");
 763         response = login_receive(conn);
 764         if (conn->conn_conf.isc_mutual_user[0] != '\0')
 765                 login_verify_mutual(response);
 766         pdu_delete(response);
 767
 768         log_debugx("CHAP authentication done");
 769 }
 770
 771 void
 772 login(struct connection *conn)
 773 {
 774         struct pdu *request, *response;
 775         struct keys *request_keys, *response_keys;
 776         struct iscsi_bhs_login_response *bhslr2;
 777         const char *auth_method;
 778         int i;
 779
 780         log_debugx("beginning Login phase; sending Login PDU");
 781         request = login_new_request(conn, BHSLR_STAGE_SECURITY_NEGOTIATION);
 782         request_keys = keys_new();
 783         if (conn->conn_conf.isc_mutual_user[0] != '\0') {
 784                 keys_add(request_keys, "AuthMethod", "CHAP");
 785         } else if (conn->conn_conf.isc_user[0] != '\0') {
 786                 /*
 787                  * Give target a chance to skip authentication if it
 788                  * doesn't feel like it.
 789                  *
 790                  * None is first, CHAP second; this is to work around
 791                  * what seems to be LIO (Linux target) bug: otherwise,
 792                  * if target is configured with no authentication,
 793                  * and we are configured to authenticate, the target
 794                  * will erroneously respond with AuthMethod=CHAP
 795                  * instead of AuthMethod=None, and will subsequently
 796                  * fail the connection.  This usually happens with
 797                  * Discovery sessions, which default to no authentication.
 798                  */
 799                 keys_add(request_keys, "AuthMethod", "None,CHAP");
 800         } else {
 801                 keys_add(request_keys, "AuthMethod", "None");
 802         }
 803         keys_add(request_keys, "InitiatorName",
 804             conn->conn_conf.isc_initiator);
 805         if (conn->conn_conf.isc_initiator_alias[0] != '\0') {
 806                 keys_add(request_keys, "InitiatorAlias",
 807                     conn->conn_conf.isc_initiator_alias);
 808         }
 809         if (conn->conn_conf.isc_discovery == 0) {
 810                 keys_add(request_keys, "SessionType", "Normal");
 811                 keys_add(request_keys,
 812                     "TargetName", conn->conn_conf.isc_target);
 813         } else {
 814                 keys_add(request_keys, "SessionType", "Discovery");
 815         }
 816         keys_save(request_keys, request);
 817         keys_delete(request_keys);
 818         pdu_send(request);
 819         pdu_delete(request);
 820
 821         response = login_receive(conn);
 822
 823         response_keys = keys_new();
 824         keys_load(response_keys, response);
 825
 826         for (i = 0; i < KEYS_MAX; i++) {
 827                 if (response_keys->keys_names[i] == NULL)
 828                         break;
 829
 830                 /*
 831                  * Not interested in AuthMethod at this point; we only need
 832                  * to parse things such as TargetAlias.
 833                  *
 834                  * XXX: This is somewhat ugly.  We should have a way to apply
 835                  *      all the keys to the session and use that by default
 836                  *      instead of discarding them.
 837                  */
 838                 if (strcmp(response_keys->keys_names[i], "AuthMethod") == 0)
 839                         continue;
 840
 841                 login_negotiate_key(conn,
 842                     response_keys->keys_names[i], response_keys->keys_values[i]);
 843         }
 844
 845         bhslr2 = (struct iscsi_bhs_login_response *)response->pdu_bhs;
 846         if ((bhslr2->bhslr_flags & BHSLR_FLAGS_TRANSIT) != 0 &&
 847             login_nsg(response) == BHSLR_STAGE_OPERATIONAL_NEGOTIATION) {
 848                 if (conn->conn_conf.isc_mutual_user[0] != '\0') {
 849                         log_errx(1, "target requested transition "
 850                             "to operational parameter negotiation, "
 851                             "but we require mutual CHAP");
 852                 }
 853
 854                 log_debugx("target requested transition "
 855                     "to operational parameter negotiation");
 856                 keys_delete(response_keys);
 857                 pdu_delete(response);
 858                 login_negotiate(conn);
 859                 return;
 860         }
 861
 862         auth_method = keys_find(response_keys, "AuthMethod");
 863         if (auth_method == NULL)
 864                 log_errx(1, "received response without AuthMethod");
 865         if (strcmp(auth_method, "None") == 0) {
 866                 if (conn->conn_conf.isc_mutual_user[0] != '\0') {
 867                         log_errx(1, "target does not require authantication, "
 868                             "but we require mutual CHAP");
 869                 }
 870
 871                 log_debugx("target does not require authentication");
 872                 keys_delete(response_keys);
 873                 pdu_delete(response);
 874                 login_negotiate(conn);
 875                 return;
 876         }
 877
 878         if (strcmp(auth_method, "CHAP") != 0) {
 879                 fail(conn, "Unsupported AuthMethod");
 880                 log_errx(1, "received response "
 881                     "with unsupported AuthMethod \"%s\"", auth_method);
 882         }
 883
 884         if (conn->conn_conf.isc_user[0] == '\0' ||
 885             conn->conn_conf.isc_secret[0] == '\0') {
 886                 fail(conn, "Authentication required");
 887                 log_errx(1, "target requests CHAP authentication, but we don't "
 888                     "have user and secret");
 889         }
 890
 891         keys_delete(response_keys);
 892         response_keys = NULL;
 893         pdu_delete(response);
 894         response = NULL;
 895
 896         login_chap(conn);
 897         login_negotiate(conn);
 898 }