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 iscsid_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 iscsid_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_pdu(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((struct iscsid_connection *)conn,
 245                     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 iscsid_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.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.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.conn_immediate_data = true;
 393                 else
 394                         conn->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.conn_max_send_data_segment_length = tmp;
 407         } else if (strcmp(name, "MaxBurstLength") == 0) {
 408                 tmp = strtoul(value, NULL, 10);
 409                 if (tmp <= 0)
 410                         log_errx(1, "received invalid MaxBurstLength");
 411                 if (tmp > isl->isl_max_burst_length) {
 412                         log_debugx("capping MaxBurstLength "
 413                             "from %d to %d", tmp, isl->isl_max_burst_length);
 414                         tmp = isl->isl_max_burst_length;
 415                 }
 416                 conn->conn.conn_max_burst_length = tmp;
 417         } else if (strcmp(name, "FirstBurstLength") == 0) {
 418                 tmp = strtoul(value, NULL, 10);
 419                 if (tmp <= 0)
 420                         log_errx(1, "received invalid FirstBurstLength");
 421                 if (tmp > isl->isl_first_burst_length) {
 422                         log_debugx("capping FirstBurstLength "
 423                             "from %d to %d", tmp, isl->isl_first_burst_length);
 424                         tmp = isl->isl_first_burst_length;
 425                 }
 426                 conn->conn.conn_first_burst_length = tmp;
 427         } else if (strcmp(name, "DefaultTime2Wait") == 0) {
 428                 /* Ignore */
 429         } else if (strcmp(name, "DefaultTime2Retain") == 0) {
 430                 /* Ignore */
 431         } else if (strcmp(name, "MaxOutstandingR2T") == 0) {
 432                 /* Ignore */
 433         } else if (strcmp(name, "DataPDUInOrder") == 0) {
 434                 /* Ignore */
 435         } else if (strcmp(name, "DataSequenceInOrder") == 0) {
 436                 /* Ignore */
 437         } else if (strcmp(name, "ErrorRecoveryLevel") == 0) {
 438                 /* Ignore */
 439         } else if (strcmp(name, "OFMarker") == 0) {
 440                 /* Ignore */
 441         } else if (strcmp(name, "IFMarker") == 0) {
 442                 /* Ignore */
 443         } else if (strcmp(name, "RDMAExtensions") == 0) {
 444                 if (conn->conn_conf.isc_iser == 1 &&
 445                     strcmp(value, "Yes") != 0) {
 446                         log_errx(1, "received unsupported RDMAExtensions");
 447                 }
 448         } else if (strcmp(name, "InitiatorRecvDataSegmentLength") == 0) {
 449                 tmp = strtoul(value, NULL, 10);
 450                 if (tmp <= 0)
 451                         log_errx(1, "received invalid "
 452                             "InitiatorRecvDataSegmentLength");
 453                 if ((int)tmp > isl->isl_max_recv_data_segment_length) {
 454                         log_debugx("capping InitiatorRecvDataSegmentLength "
 455                             "from %d to %d", tmp,
 456                             isl->isl_max_recv_data_segment_length);
 457                         tmp = isl->isl_max_recv_data_segment_length;
 458                 }
 459                 conn->conn.conn_max_recv_data_segment_length = tmp;
 460         } else if (strcmp(name, "TargetPortalGroupTag") == 0) {
 461                 /* Ignore */
 462         } else if (strcmp(name, "TargetRecvDataSegmentLength") == 0) {
 463                 tmp = strtoul(value, NULL, 10);
 464                 if (tmp <= 0) {
 465                         log_errx(1,
 466                             "received invalid TargetRecvDataSegmentLength");
 467                 }
 468                 if (tmp > isl->isl_max_send_data_segment_length) {
 469                         log_debugx("capping TargetRecvDataSegmentLength "
 470                             "from %d to %d", tmp,
 471                             isl->isl_max_send_data_segment_length);
 472                         tmp = isl->isl_max_send_data_segment_length;
 473                 }
 474                 conn->conn.conn_max_send_data_segment_length = tmp;
 475         } else {
 476                 log_debugx("unknown key \"%s\"; ignoring",  name);
 477         }
 478 }
 479
 480 static void
 481 login_negotiate(struct iscsid_connection *conn)
 482 {
 483         struct pdu *request, *response;
 484         struct keys *request_keys, *response_keys;
 485         struct iscsi_bhs_login_response *bhslr;
 486         int i, nrequests = 0;
 487         struct iscsi_session_limits *isl;
 488
 489         log_debugx("beginning operational parameter negotiation");
 490         request = login_new_request(&conn->conn,
 491             BHSLR_STAGE_OPERATIONAL_NEGOTIATION);
 492         request_keys = keys_new();
 493
 494         isl = &conn->conn_limits;
 495         log_debugx("Limits for offload \"%s\" are "
 496             "MaxRecvDataSegment=%d, max_send_dsl=%d, "
 497             "MaxBurstLength=%d, FirstBurstLength=%d",
 498             conn->conn_conf.isc_offload, isl->isl_max_recv_data_segment_length,
 499             isl->isl_max_send_data_segment_length, isl->isl_max_burst_length,
 500             isl->isl_first_burst_length);
 501
 502         /*
 503          * The following keys are irrelevant for discovery sessions.
 504          */
 505         if (conn->conn_conf.isc_discovery == 0) {
 506                 keys_add(request_keys, "iSCSIProtocolLevel", "2");
 507                 if (conn->conn_conf.isc_header_digest != 0)
 508                         keys_add(request_keys, "HeaderDigest", "CRC32C");
 509                 else
 510                         keys_add(request_keys, "HeaderDigest", "None");
 511                 if (conn->conn_conf.isc_data_digest != 0)
 512                         keys_add(request_keys, "DataDigest", "CRC32C");
 513                 else
 514                         keys_add(request_keys, "DataDigest", "None");
 515
 516                 keys_add(request_keys, "ImmediateData", "Yes");
 517                 keys_add_int(request_keys, "MaxBurstLength",
 518                     isl->isl_max_burst_length);
 519                 keys_add_int(request_keys, "FirstBurstLength",
 520                     isl->isl_first_burst_length);
 521                 keys_add(request_keys, "InitialR2T", "Yes");
 522                 keys_add(request_keys, "MaxOutstandingR2T", "1");
 523                 if (conn->conn_conf.isc_iser == 1) {
 524                         keys_add_int(request_keys, "InitiatorRecvDataSegmentLength",
 525                             isl->isl_max_recv_data_segment_length);
 526                         keys_add_int(request_keys, "TargetRecvDataSegmentLength",
 527                             isl->isl_max_send_data_segment_length);
 528                         keys_add(request_keys, "RDMAExtensions", "Yes");
 529                 } else {
 530                         keys_add_int(request_keys, "MaxRecvDataSegmentLength",
 531                             isl->isl_max_recv_data_segment_length);
 532                 }
 533         } else {
 534                 keys_add(request_keys, "HeaderDigest", "None");
 535                 keys_add(request_keys, "DataDigest", "None");
 536                 keys_add_int(request_keys, "MaxRecvDataSegmentLength",
 537                     isl->isl_max_recv_data_segment_length);
 538         }
 539
 540         conn->conn.conn_max_recv_data_segment_length =
 541             isl->isl_max_recv_data_segment_length;
 542
 543         keys_add(request_keys, "DefaultTime2Wait", "0");
 544         keys_add(request_keys, "DefaultTime2Retain", "0");
 545         keys_add(request_keys, "ErrorRecoveryLevel", "0");
 546         keys_save_pdu(request_keys, request);
 547         keys_delete(request_keys);
 548         request_keys = NULL;
 549         pdu_send(request);
 550         pdu_delete(request);
 551         request = NULL;
 552
 553         response = login_receive(&conn->conn);
 554         response_keys = keys_new();
 555         keys_load_pdu(response_keys, response);
 556         for (i = 0; i < KEYS_MAX; i++) {
 557                 if (response_keys->keys_names[i] == NULL)
 558                         break;
 559
 560                 login_negotiate_key(conn,
 561                     response_keys->keys_names[i], response_keys->keys_values[i]);
 562         }
 563
 564         keys_delete(response_keys);
 565         response_keys = NULL;
 566
 567         for (;;) {
 568                 bhslr = (struct iscsi_bhs_login_response *)response->pdu_bhs;
 569                 if ((bhslr->bhslr_flags & BHSLR_FLAGS_TRANSIT) != 0)
 570                         break;
 571
 572                 nrequests++;
 573                 if (nrequests > 5) {
 574                         log_warnx("received login response "
 575                             "without the \"T\" flag too many times; giving up");
 576                         break;
 577                 }
 578
 579                 log_debugx("received login response "
 580                     "without the \"T\" flag; sending another request");
 581
 582                 pdu_delete(response);
 583
 584                 request = login_new_request(&conn->conn,
 585                     BHSLR_STAGE_OPERATIONAL_NEGOTIATION);
 586                 pdu_send(request);
 587                 pdu_delete(request);
 588
 589                 response = login_receive(&conn->conn);
 590         }
 591
 592         if (login_nsg(response) != BHSLR_STAGE_FULL_FEATURE_PHASE)
 593                 log_warnx("received final login response with wrong NSG 0x%x",
 594                     login_nsg(response));
 595         pdu_delete(response);
 596
 597         log_debugx("operational parameter negotiation done; "
 598             "transitioning to Full Feature phase");
 599 }
 600
 601 static void
 602 login_send_chap_a(struct connection *conn)
 603 {
 604         struct pdu *request;
 605         struct keys *request_keys;
 606
 607         request = login_new_request(conn, BHSLR_STAGE_SECURITY_NEGOTIATION);
 608         request_keys = keys_new();
 609         keys_add(request_keys, "CHAP_A", "5");
 610         keys_save_pdu(request_keys, request);
 611         keys_delete(request_keys);
 612         pdu_send(request);
 613         pdu_delete(request);
 614 }
 615
 616 static void
 617 login_send_chap_r(struct pdu *response)
 618 {
 619         struct iscsid_connection *conn;
 620         struct pdu *request;
 621         struct keys *request_keys, *response_keys;
 622         struct rchap *rchap;
 623         const char *chap_a, *chap_c, *chap_i;
 624         char *chap_r;
 625         int error;
 626         char *mutual_chap_c, *mutual_chap_i;
 627
 628         /*
 629          * As in the rest of the initiator, 'request' means
 630          * 'initiator -> target', and 'response' means 'target -> initiator',
 631          *
 632          * So, here the 'response' from the target is the packet that contains
 633          * CHAP challenge; our CHAP response goes into 'request'.
 634          */
 635
 636         conn = (struct iscsid_connection *)response->pdu_connection;
 637
 638         response_keys = keys_new();
 639         keys_load_pdu(response_keys, response);
 640
 641         /*
 642          * First, compute the response.
 643          */
 644         chap_a = keys_find(response_keys, "CHAP_A");
 645         if (chap_a == NULL)
 646                 log_errx(1, "received CHAP packet without CHAP_A");
 647         chap_c = keys_find(response_keys, "CHAP_C");
 648         if (chap_c == NULL)
 649                 log_errx(1, "received CHAP packet without CHAP_C");
 650         chap_i = keys_find(response_keys, "CHAP_I");
 651         if (chap_i == NULL)
 652                 log_errx(1, "received CHAP packet without CHAP_I");
 653
 654         if (strcmp(chap_a, "5") != 0) {
 655                 log_errx(1, "received CHAP packet "
 656                     "with unsupported CHAP_A \"%s\"", chap_a);
 657         }
 658
 659         rchap = rchap_new(conn->conn_conf.isc_secret);
 660         error = rchap_receive(rchap, chap_i, chap_c);
 661         if (error != 0) {
 662                 log_errx(1, "received CHAP packet "
 663                     "with malformed CHAP_I or CHAP_C");
 664         }
 665         chap_r = rchap_get_response(rchap);
 666         rchap_delete(rchap);
 667
 668         keys_delete(response_keys);
 669
 670         request = login_new_request(&conn->conn,
 671             BHSLR_STAGE_SECURITY_NEGOTIATION);
 672         request_keys = keys_new();
 673         keys_add(request_keys, "CHAP_N", conn->conn_conf.isc_user);
 674         keys_add(request_keys, "CHAP_R", chap_r);
 675         free(chap_r);
 676
 677         /*
 678          * If we want mutual authentication, we're expected to send
 679          * our CHAP_I/CHAP_C now.
 680          */
 681         if (conn->conn_conf.isc_mutual_user[0] != '\0') {
 682                 log_debugx("requesting mutual authentication; "
 683                     "binary challenge size is %zd bytes",
 684                     sizeof(conn->conn_mutual_chap->chap_challenge));
 685
 686                 assert(conn->conn_mutual_chap == NULL);
 687                 conn->conn_mutual_chap = chap_new();
 688                 mutual_chap_i = chap_get_id(conn->conn_mutual_chap);
 689                 mutual_chap_c = chap_get_challenge(conn->conn_mutual_chap);
 690                 keys_add(request_keys, "CHAP_I", mutual_chap_i);
 691                 keys_add(request_keys, "CHAP_C", mutual_chap_c);
 692                 free(mutual_chap_i);
 693                 free(mutual_chap_c);
 694         }
 695
 696         keys_save_pdu(request_keys, request);
 697         keys_delete(request_keys);
 698         pdu_send(request);
 699         pdu_delete(request);
 700 }
 701
 702 static void
 703 login_verify_mutual(const struct pdu *response)
 704 {
 705         struct iscsid_connection *conn;
 706         struct keys *response_keys;
 707         const char *chap_n, *chap_r;
 708         int error;
 709
 710         conn = (struct iscsid_connection *)response->pdu_connection;
 711
 712         response_keys = keys_new();
 713         keys_load_pdu(response_keys, response);
 714
 715         chap_n = keys_find(response_keys, "CHAP_N");
 716         if (chap_n == NULL)
 717                 log_errx(1, "received CHAP Response PDU without CHAP_N");
 718         chap_r = keys_find(response_keys, "CHAP_R");
 719         if (chap_r == NULL)
 720                 log_errx(1, "received CHAP Response PDU without CHAP_R");
 721
 722         error = chap_receive(conn->conn_mutual_chap, chap_r);
 723         if (error != 0)
 724                 log_errx(1, "received CHAP Response PDU with invalid CHAP_R");
 725
 726         if (strcmp(chap_n, conn->conn_conf.isc_mutual_user) != 0) {
 727                 fail(&conn->conn, "Mutual CHAP failed");
 728                 log_errx(1, "mutual CHAP authentication failed: wrong user");
 729         }
 730
 731         error = chap_authenticate(conn->conn_mutual_chap,
 732             conn->conn_conf.isc_mutual_secret);
 733         if (error != 0) {
 734                 fail(&conn->conn, "Mutual CHAP failed");
 735                 log_errx(1, "mutual CHAP authentication failed: wrong secret");
 736         }
 737
 738         keys_delete(response_keys);
 739         chap_delete(conn->conn_mutual_chap);
 740         conn->conn_mutual_chap = NULL;
 741
 742         log_debugx("mutual CHAP authentication succeeded");
 743 }
 744
 745 static void
 746 login_chap(struct iscsid_connection *conn)
 747 {
 748         struct pdu *response;
 749
 750         log_debugx("beginning CHAP authentication; sending CHAP_A");
 751         login_send_chap_a(&conn->conn);
 752
 753         log_debugx("waiting for CHAP_A/CHAP_C/CHAP_I");
 754         response = login_receive(&conn->conn);
 755
 756         log_debugx("sending CHAP_N/CHAP_R");
 757         login_send_chap_r(response);
 758         pdu_delete(response);
 759
 760         /*
 761          * XXX: Make sure this is not susceptible to MITM.
 762          */
 763
 764         log_debugx("waiting for CHAP result");
 765         response = login_receive(&conn->conn);
 766         if (conn->conn_conf.isc_mutual_user[0] != '\0')
 767                 login_verify_mutual(response);
 768         pdu_delete(response);
 769
 770         log_debugx("CHAP authentication done");
 771 }
 772
 773 void
 774 login(struct iscsid_connection *conn)
 775 {
 776         struct pdu *request, *response;
 777         struct keys *request_keys, *response_keys;
 778         struct iscsi_bhs_login_response *bhslr2;
 779         const char *auth_method;
 780         int i;
 781
 782         log_debugx("beginning Login phase; sending Login PDU");
 783         request = login_new_request(&conn->conn,
 784             BHSLR_STAGE_SECURITY_NEGOTIATION);
 785         request_keys = keys_new();
 786         if (conn->conn_conf.isc_mutual_user[0] != '\0') {
 787                 keys_add(request_keys, "AuthMethod", "CHAP");
 788         } else if (conn->conn_conf.isc_user[0] != '\0') {
 789                 /*
 790                  * Give target a chance to skip authentication if it
 791                  * doesn't feel like it.
 792                  *
 793                  * None is first, CHAP second; this is to work around
 794                  * what seems to be LIO (Linux target) bug: otherwise,
 795                  * if target is configured with no authentication,
 796                  * and we are configured to authenticate, the target
 797                  * will erroneously respond with AuthMethod=CHAP
 798                  * instead of AuthMethod=None, and will subsequently
 799                  * fail the connection.  This usually happens with
 800                  * Discovery sessions, which default to no authentication.
 801                  */
 802                 keys_add(request_keys, "AuthMethod", "None,CHAP");
 803         } else {
 804                 keys_add(request_keys, "AuthMethod", "None");
 805         }
 806         keys_add(request_keys, "InitiatorName",
 807             conn->conn_conf.isc_initiator);
 808         if (conn->conn_conf.isc_initiator_alias[0] != '\0') {
 809                 keys_add(request_keys, "InitiatorAlias",
 810                     conn->conn_conf.isc_initiator_alias);
 811         }
 812         if (conn->conn_conf.isc_discovery == 0) {
 813                 keys_add(request_keys, "SessionType", "Normal");
 814                 keys_add(request_keys,
 815                     "TargetName", conn->conn_conf.isc_target);
 816         } else {
 817                 keys_add(request_keys, "SessionType", "Discovery");
 818         }
 819         keys_save_pdu(request_keys, request);
 820         keys_delete(request_keys);
 821         pdu_send(request);
 822         pdu_delete(request);
 823
 824         response = login_receive(&conn->conn);
 825
 826         response_keys = keys_new();
 827         keys_load_pdu(response_keys, response);
 828
 829         for (i = 0; i < KEYS_MAX; i++) {
 830                 if (response_keys->keys_names[i] == NULL)
 831                         break;
 832
 833                 /*
 834                  * Not interested in AuthMethod at this point; we only need
 835                  * to parse things such as TargetAlias.
 836                  *
 837                  * XXX: This is somewhat ugly.  We should have a way to apply
 838                  *      all the keys to the session and use that by default
 839                  *      instead of discarding them.
 840                  */
 841                 if (strcmp(response_keys->keys_names[i], "AuthMethod") == 0)
 842                         continue;
 843
 844                 login_negotiate_key(conn,
 845                     response_keys->keys_names[i], response_keys->keys_values[i]);
 846         }
 847
 848         bhslr2 = (struct iscsi_bhs_login_response *)response->pdu_bhs;
 849         if ((bhslr2->bhslr_flags & BHSLR_FLAGS_TRANSIT) != 0 &&
 850             login_nsg(response) == BHSLR_STAGE_OPERATIONAL_NEGOTIATION) {
 851                 if (conn->conn_conf.isc_mutual_user[0] != '\0') {
 852                         log_errx(1, "target requested transition "
 853                             "to operational parameter negotiation, "
 854                             "but we require mutual CHAP");
 855                 }
 856
 857                 log_debugx("target requested transition "
 858                     "to operational parameter negotiation");
 859                 keys_delete(response_keys);
 860                 pdu_delete(response);
 861                 login_negotiate(conn);
 862                 return;
 863         }
 864
 865         auth_method = keys_find(response_keys, "AuthMethod");
 866         if (auth_method == NULL)
 867                 log_errx(1, "received response without AuthMethod");
 868         if (strcmp(auth_method, "None") == 0) {
 869                 if (conn->conn_conf.isc_mutual_user[0] != '\0') {
 870                         log_errx(1, "target does not require authantication, "
 871                             "but we require mutual CHAP");
 872                 }
 873
 874                 log_debugx("target does not require authentication");
 875                 keys_delete(response_keys);
 876                 pdu_delete(response);
 877                 login_negotiate(conn);
 878                 return;
 879         }
 880
 881         if (strcmp(auth_method, "CHAP") != 0) {
 882                 fail(&conn->conn, "Unsupported AuthMethod");
 883                 log_errx(1, "received response "
 884                     "with unsupported AuthMethod \"%s\"", auth_method);
 885         }
 886
 887         if (conn->conn_conf.isc_user[0] == '\0' ||
 888             conn->conn_conf.isc_secret[0] == '\0') {
 889                 fail(&conn->conn, "Authentication required");
 890                 log_errx(1, "target requests CHAP authentication, but we don't "
 891                     "have user and secret");
 892         }
 893
 894         keys_delete(response_keys);
 895         response_keys = NULL;
 896         pdu_delete(response);
 897         response = NULL;
 898
 899         login_chap(conn);
 900         login_negotiate(conn);
 901 }