drivers/scsi/scsi_transport_iscsi.c

   1 /*
   2  * iSCSI transport class definitions
   3  *
   4  * Copyright (C) IBM Corporation, 2004
   5  * Copyright (C) Mike Christie, 2004 - 2005
   6  * Copyright (C) Dmitry Yusupov, 2004 - 2005
   7  * Copyright (C) Alex Aizman, 2004 - 2005
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  22  */
  23 #include <linux/module.h>
  24 #include <linux/mutex.h>
  25 #include <net/tcp.h>
  26 #include <scsi/scsi.h>
  27 #include <scsi/scsi_host.h>
  28 #include <scsi/scsi_device.h>
  29 #include <scsi/scsi_transport.h>
  30 #include <scsi/scsi_transport_iscsi.h>
  31 #include <scsi/iscsi_if.h>
  32
  33 #define ISCSI_SESSION_ATTRS 19
  34 #define ISCSI_CONN_ATTRS 13
  35 #define ISCSI_HOST_ATTRS 4
  36 #define ISCSI_TRANSPORT_VERSION "2.0-868"
  37
  38 struct iscsi_internal {
  39         int daemon_pid;
  40         struct scsi_transport_template t;
  41         struct iscsi_transport *iscsi_transport;
  42         struct list_head list;
  43         struct class_device cdev;
  44
  45         struct class_device_attribute *host_attrs[ISCSI_HOST_ATTRS + 1];
  46         struct transport_container conn_cont;
  47         struct class_device_attribute *conn_attrs[ISCSI_CONN_ATTRS + 1];
  48         struct transport_container session_cont;
  49         struct class_device_attribute *session_attrs[ISCSI_SESSION_ATTRS + 1];
  50 };
  51
  52 static atomic_t iscsi_session_nr; /* sysfs session id for next new session */
  53 static struct workqueue_struct *iscsi_eh_timer_workq;
  54
  55 /*
  56  * list of registered transports and lock that must
  57  * be held while accessing list. The iscsi_transport_lock must
  58  * be acquired after the rx_queue_mutex.
  59  */
  60 static LIST_HEAD(iscsi_transports);
  61 static DEFINE_SPINLOCK(iscsi_transport_lock);
  62
  63 #define to_iscsi_internal(tmpl) \
  64         container_of(tmpl, struct iscsi_internal, t)
  65
  66 #define cdev_to_iscsi_internal(_cdev) \
  67         container_of(_cdev, struct iscsi_internal, cdev)
  68
  69 static void iscsi_transport_release(struct class_device *cdev)
  70 {
  71         struct iscsi_internal *priv = cdev_to_iscsi_internal(cdev);
  72         kfree(priv);
  73 }
  74
  75 /*
  76  * iscsi_transport_class represents the iscsi_transports that are
  77  * registered.
  78  */
  79 static struct class iscsi_transport_class = {
  80         .name = "iscsi_transport",
  81         .release = iscsi_transport_release,
  82 };
  83
  84 static ssize_t
  85 show_transport_handle(struct class_device *cdev, char *buf)
  86 {
  87         struct iscsi_internal *priv = cdev_to_iscsi_internal(cdev);
  88         return sprintf(buf, "%llu\n", (unsigned long long)iscsi_handle(priv->iscsi_transport));
  89 }
  90 static CLASS_DEVICE_ATTR(handle, S_IRUGO, show_transport_handle, NULL);
  91
  92 #define show_transport_attr(name, format)                               \
  93 static ssize_t                                                          \
  94 show_transport_##name(struct class_device *cdev, char *buf)             \
  95 {                                                                       \
  96         struct iscsi_internal *priv = cdev_to_iscsi_internal(cdev);     \
  97         return sprintf(buf, format"\n", priv->iscsi_transport->name);   \
  98 }                                                                       \
  99 static CLASS_DEVICE_ATTR(name, S_IRUGO, show_transport_##name, NULL);
 100
 101 show_transport_attr(caps, "0x%x");
 102 show_transport_attr(max_lun, "%d");
 103 show_transport_attr(max_conn, "%d");
 104 show_transport_attr(max_cmd_len, "%d");
 105
 106 static struct attribute *iscsi_transport_attrs[] = {
 107         &class_device_attr_handle.attr,
 108         &class_device_attr_caps.attr,
 109         &class_device_attr_max_lun.attr,
 110         &class_device_attr_max_conn.attr,
 111         &class_device_attr_max_cmd_len.attr,
 112         NULL,
 113 };
 114
 115 static struct attribute_group iscsi_transport_group = {
 116         .attrs = iscsi_transport_attrs,
 117 };
 118
 119
 120
 121 static int iscsi_setup_host(struct transport_container *tc, struct device *dev,
 122                             struct class_device *cdev)
 123 {
 124         struct Scsi_Host *shost = dev_to_shost(dev);
 125         struct iscsi_host *ihost = shost->shost_data;
 126
 127         memset(ihost, 0, sizeof(*ihost));
 128         INIT_LIST_HEAD(&ihost->sessions);
 129         mutex_init(&ihost->mutex);
 130         atomic_set(&ihost->nr_scans, 0);
 131
 132         snprintf(ihost->scan_workq_name, KOBJ_NAME_LEN, "iscsi_scan_%d",
 133                 shost->host_no);
 134         ihost->scan_workq = create_singlethread_workqueue(
 135                                                 ihost->scan_workq_name);
 136         if (!ihost->scan_workq)
 137                 return -ENOMEM;
 138         return 0;
 139 }
 140
 141 static int iscsi_remove_host(struct transport_container *tc, struct device *dev,
 142                              struct class_device *cdev)
 143 {
 144         struct Scsi_Host *shost = dev_to_shost(dev);
 145         struct iscsi_host *ihost = shost->shost_data;
 146
 147         destroy_workqueue(ihost->scan_workq);
 148         return 0;
 149 }
 150
 151 static DECLARE_TRANSPORT_CLASS(iscsi_host_class,
 152                                "iscsi_host",
 153                                iscsi_setup_host,
 154                                iscsi_remove_host,
 155                                NULL);
 156
 157 static DECLARE_TRANSPORT_CLASS(iscsi_session_class,
 158                                "iscsi_session",
 159                                NULL,
 160                                NULL,
 161                                NULL);
 162
 163 static DECLARE_TRANSPORT_CLASS(iscsi_connection_class,
 164                                "iscsi_connection",
 165                                NULL,
 166                                NULL,
 167                                NULL);
 168
 169 static struct sock *nls;
 170 static DEFINE_MUTEX(rx_queue_mutex);
 171
 172 static LIST_HEAD(sesslist);
 173 static DEFINE_SPINLOCK(sesslock);
 174 static LIST_HEAD(connlist);
 175 static DEFINE_SPINLOCK(connlock);
 176
 177 static uint32_t iscsi_conn_get_sid(struct iscsi_cls_conn *conn)
 178 {
 179         struct iscsi_cls_session *sess = iscsi_dev_to_session(conn->dev.parent);
 180         return sess->sid;
 181 }
 182
 183 /*
 184  * Returns the matching session to a given sid
 185  */
 186 static struct iscsi_cls_session *iscsi_session_lookup(uint32_t sid)
 187 {
 188         unsigned long flags;
 189         struct iscsi_cls_session *sess;
 190
 191         spin_lock_irqsave(&sesslock, flags);
 192         list_for_each_entry(sess, &sesslist, sess_list) {
 193                 if (sess->sid == sid) {
 194                         spin_unlock_irqrestore(&sesslock, flags);
 195                         return sess;
 196                 }
 197         }
 198         spin_unlock_irqrestore(&sesslock, flags);
 199         return NULL;
 200 }
 201
 202 /*
 203  * Returns the matching connection to a given sid / cid tuple
 204  */
 205 static struct iscsi_cls_conn *iscsi_conn_lookup(uint32_t sid, uint32_t cid)
 206 {
 207         unsigned long flags;
 208         struct iscsi_cls_conn *conn;
 209
 210         spin_lock_irqsave(&connlock, flags);
 211         list_for_each_entry(conn, &connlist, conn_list) {
 212                 if ((conn->cid == cid) && (iscsi_conn_get_sid(conn) == sid)) {
 213                         spin_unlock_irqrestore(&connlock, flags);
 214                         return conn;
 215                 }
 216         }
 217         spin_unlock_irqrestore(&connlock, flags);
 218         return NULL;
 219 }
 220
 221 /*
 222  * The following functions can be used by LLDs that allocate
 223  * their own scsi_hosts or by software iscsi LLDs
 224  */
 225 static struct {
 226         int value;
 227         char *name;
 228 } iscsi_session_state_names[] = {
 229         { ISCSI_SESSION_LOGGED_IN,      "LOGGED_IN" },
 230         { ISCSI_SESSION_FAILED,         "FAILED" },
 231         { ISCSI_SESSION_FREE,           "FREE" },
 232 };
 233
 234 const char *iscsi_session_state_name(int state)
 235 {
 236         int i;
 237         char *name = NULL;
 238
 239         for (i = 0; i < ARRAY_SIZE(iscsi_session_state_names); i++) {
 240                 if (iscsi_session_state_names[i].value == state) {
 241                         name = iscsi_session_state_names[i].name;
 242                         break;
 243                 }
 244         }
 245         return name;
 246 }
 247
 248 int iscsi_session_chkready(struct iscsi_cls_session *session)
 249 {
 250         unsigned long flags;
 251         int err;
 252
 253         spin_lock_irqsave(&session->lock, flags);
 254         switch (session->state) {
 255         case ISCSI_SESSION_LOGGED_IN:
 256                 err = 0;
 257                 break;
 258         case ISCSI_SESSION_FAILED:
 259                 err = DID_IMM_RETRY << 16;
 260                 break;
 261         case ISCSI_SESSION_FREE:
 262                 err = DID_NO_CONNECT << 16;
 263                 break;
 264         default:
 265                 err = DID_NO_CONNECT << 16;
 266                 break;
 267         }
 268         spin_unlock_irqrestore(&session->lock, flags);
 269         return err;
 270 }
 271 EXPORT_SYMBOL_GPL(iscsi_session_chkready);
 272
 273 static void iscsi_session_release(struct device *dev)
 274 {
 275         struct iscsi_cls_session *session = iscsi_dev_to_session(dev);
 276         struct Scsi_Host *shost;
 277
 278         shost = iscsi_session_to_shost(session);
 279         scsi_host_put(shost);
 280         kfree(session);
 281 }
 282
 283 static int iscsi_is_session_dev(const struct device *dev)
 284 {
 285         return dev->release == iscsi_session_release;
 286 }
 287
 288 /**
 289  * iscsi_scan_finished - helper to report when running scans are done
 290  * @shost: scsi host
 291  * @time: scan run time
 292  *
 293  * This function can be used by drives like qla4xxx to report to the scsi
 294  * layer when the scans it kicked off at module load time are done.
 295  */
 296 int iscsi_scan_finished(struct Scsi_Host *shost, unsigned long time)
 297 {
 298         struct iscsi_host *ihost = shost->shost_data;
 299         /*
 300          * qla4xxx will have kicked off some session unblocks before calling
 301          * scsi_scan_host, so just wait for them to complete.
 302          */
 303         return !atomic_read(&ihost->nr_scans);
 304 }
 305 EXPORT_SYMBOL_GPL(iscsi_scan_finished);
 306
 307 static int iscsi_user_scan(struct Scsi_Host *shost, uint channel,
 308                            uint id, uint lun)
 309 {
 310         struct iscsi_host *ihost = shost->shost_data;
 311         struct iscsi_cls_session *session;
 312
 313         mutex_lock(&ihost->mutex);
 314         list_for_each_entry(session, &ihost->sessions, host_list) {
 315                 if ((channel == SCAN_WILD_CARD || channel == 0) &&
 316                     (id == SCAN_WILD_CARD || id == session->target_id))
 317                         scsi_scan_target(&session->dev, 0,
 318                                          session->target_id, lun, 1);
 319         }
 320         mutex_unlock(&ihost->mutex);
 321
 322         return 0;
 323 }
 324
 325 static void iscsi_scan_session(struct work_struct *work)
 326 {
 327         struct iscsi_cls_session *session =
 328                         container_of(work, struct iscsi_cls_session, scan_work);
 329         struct Scsi_Host *shost = iscsi_session_to_shost(session);
 330         struct iscsi_host *ihost = shost->shost_data;
 331         unsigned long flags;
 332
 333         spin_lock_irqsave(&session->lock, flags);
 334         if (session->state != ISCSI_SESSION_LOGGED_IN) {
 335                 spin_unlock_irqrestore(&session->lock, flags);
 336                 goto done;
 337         }
 338         spin_unlock_irqrestore(&session->lock, flags);
 339
 340         scsi_scan_target(&session->dev, 0, session->target_id,
 341                          SCAN_WILD_CARD, 1);
 342 done:
 343         atomic_dec(&ihost->nr_scans);
 344 }
 345
 346 static void session_recovery_timedout(struct work_struct *work)
 347 {
 348         struct iscsi_cls_session *session =
 349                 container_of(work, struct iscsi_cls_session,
 350                              recovery_work.work);
 351         unsigned long flags;
 352
 353         iscsi_cls_session_printk(KERN_INFO, session,
 354                                  "session recovery timed out after %d secs\n",
 355                                  session->recovery_tmo);
 356
 357         spin_lock_irqsave(&session->lock, flags);
 358         switch (session->state) {
 359         case ISCSI_SESSION_FAILED:
 360                 session->state = ISCSI_SESSION_FREE;
 361                 break;
 362         case ISCSI_SESSION_LOGGED_IN:
 363         case ISCSI_SESSION_FREE:
 364                 /* we raced with the unblock's flush */
 365                 spin_unlock_irqrestore(&session->lock, flags);
 366                 return;
 367         }
 368         spin_unlock_irqrestore(&session->lock, flags);
 369
 370         if (session->transport->session_recovery_timedout)
 371                 session->transport->session_recovery_timedout(session);
 372
 373         scsi_target_unblock(&session->dev);
 374 }
 375
 376 void __iscsi_unblock_session(struct iscsi_cls_session *session)
 377 {
 378         if (!cancel_delayed_work(&session->recovery_work))
 379                 flush_workqueue(iscsi_eh_timer_workq);
 380         scsi_target_unblock(&session->dev);
 381 }
 382
 383 void iscsi_unblock_session(struct iscsi_cls_session *session)
 384 {
 385         struct Scsi_Host *shost = iscsi_session_to_shost(session);
 386         struct iscsi_host *ihost = shost->shost_data;
 387         unsigned long flags;
 388
 389         spin_lock_irqsave(&session->lock, flags);
 390         session->state = ISCSI_SESSION_LOGGED_IN;
 391         spin_unlock_irqrestore(&session->lock, flags);
 392
 393         __iscsi_unblock_session(session);
 394         /*
 395          * Only do kernel scanning if the driver is properly hooked into
 396          * the async scanning code (drivers like iscsi_tcp do login and
 397          * scanning from userspace).
 398          */
 399         if (shost->hostt->scan_finished) {
 400                 if (queue_work(ihost->scan_workq, &session->scan_work))
 401                         atomic_inc(&ihost->nr_scans);
 402         }
 403 }
 404 EXPORT_SYMBOL_GPL(iscsi_unblock_session);
 405
 406 void iscsi_block_session(struct iscsi_cls_session *session)
 407 {
 408         unsigned long flags;
 409
 410         spin_lock_irqsave(&session->lock, flags);
 411         session->state = ISCSI_SESSION_FAILED;
 412         spin_unlock_irqrestore(&session->lock, flags);
 413
 414         scsi_target_block(&session->dev);
 415         queue_delayed_work(iscsi_eh_timer_workq, &session->recovery_work,
 416                            session->recovery_tmo * HZ);
 417 }
 418 EXPORT_SYMBOL_GPL(iscsi_block_session);
 419
 420 static void __iscsi_unbind_session(struct work_struct *work)
 421 {
 422         struct iscsi_cls_session *session =
 423                         container_of(work, struct iscsi_cls_session,
 424                                      unbind_work);
 425         struct Scsi_Host *shost = iscsi_session_to_shost(session);
 426         struct iscsi_host *ihost = shost->shost_data;
 427
 428         /* Prevent new scans and make sure scanning is not in progress */
 429         mutex_lock(&ihost->mutex);
 430         if (list_empty(&session->host_list)) {
 431                 mutex_unlock(&ihost->mutex);
 432                 return;
 433         }
 434         list_del_init(&session->host_list);
 435         mutex_unlock(&ihost->mutex);
 436
 437         scsi_remove_target(&session->dev);
 438         iscsi_session_event(session, ISCSI_KEVENT_UNBIND_SESSION);
 439 }
 440
 441 static int iscsi_unbind_session(struct iscsi_cls_session *session)
 442 {
 443         struct Scsi_Host *shost = iscsi_session_to_shost(session);
 444         struct iscsi_host *ihost = shost->shost_data;
 445
 446         return queue_work(ihost->scan_workq, &session->unbind_work);
 447 }
 448
 449 struct iscsi_cls_session *
 450 iscsi_alloc_session(struct Scsi_Host *shost,
 451                     struct iscsi_transport *transport)
 452 {
 453         struct iscsi_cls_session *session;
 454
 455         session = kzalloc(sizeof(*session) + transport->sessiondata_size,
 456                           GFP_KERNEL);
 457         if (!session)
 458                 return NULL;
 459
 460         session->transport = transport;
 461         session->recovery_tmo = 120;
 462         session->state = ISCSI_SESSION_FREE;
 463         INIT_DELAYED_WORK(&session->recovery_work, session_recovery_timedout);
 464         INIT_LIST_HEAD(&session->host_list);
 465         INIT_LIST_HEAD(&session->sess_list);
 466         INIT_WORK(&session->unbind_work, __iscsi_unbind_session);
 467         INIT_WORK(&session->scan_work, iscsi_scan_session);
 468         spin_lock_init(&session->lock);
 469
 470         /* this is released in the dev's release function */
 471         scsi_host_get(shost);
 472         session->dev.parent = &shost->shost_gendev;
 473         session->dev.release = iscsi_session_release;
 474         device_initialize(&session->dev);
 475         if (transport->sessiondata_size)
 476                 session->dd_data = &session[1];
 477         return session;
 478 }
 479 EXPORT_SYMBOL_GPL(iscsi_alloc_session);
 480
 481 int iscsi_add_session(struct iscsi_cls_session *session, unsigned int target_id)
 482 {
 483         struct Scsi_Host *shost = iscsi_session_to_shost(session);
 484         struct iscsi_host *ihost;
 485         unsigned long flags;
 486         int err;
 487
 488         ihost = shost->shost_data;
 489         session->sid = atomic_add_return(1, &iscsi_session_nr);
 490         session->target_id = target_id;
 491
 492         snprintf(session->dev.bus_id, BUS_ID_SIZE, "session%u",
 493                  session->sid);
 494         err = device_add(&session->dev);
 495         if (err) {
 496                 iscsi_cls_session_printk(KERN_ERR, session,
 497                                          "could not register session's dev\n");
 498                 goto release_host;
 499         }
 500         transport_register_device(&session->dev);
 501
 502         spin_lock_irqsave(&sesslock, flags);
 503         list_add(&session->sess_list, &sesslist);
 504         spin_unlock_irqrestore(&sesslock, flags);
 505
 506         mutex_lock(&ihost->mutex);
 507         list_add(&session->host_list, &ihost->sessions);
 508         mutex_unlock(&ihost->mutex);
 509
 510         iscsi_session_event(session, ISCSI_KEVENT_CREATE_SESSION);
 511         return 0;
 512
 513 release_host:
 514         scsi_host_put(shost);
 515         return err;
 516 }
 517 EXPORT_SYMBOL_GPL(iscsi_add_session);
 518
 519 /**
 520  * iscsi_create_session - create iscsi class session
 521  * @shost: scsi host
 522  * @transport: iscsi transport
 523  * @target_id: which target
 524  *
 525  * This can be called from a LLD or iscsi_transport.
 526  */
 527 struct iscsi_cls_session *
 528 iscsi_create_session(struct Scsi_Host *shost,
 529                      struct iscsi_transport *transport,
 530                      unsigned int target_id)
 531 {
 532         struct iscsi_cls_session *session;
 533
 534         session = iscsi_alloc_session(shost, transport);
 535         if (!session)
 536                 return NULL;
 537
 538         if (iscsi_add_session(session, target_id)) {
 539                 iscsi_free_session(session);
 540                 return NULL;
 541         }
 542         return session;
 543 }
 544 EXPORT_SYMBOL_GPL(iscsi_create_session);
 545
 546 static void iscsi_conn_release(struct device *dev)
 547 {
 548         struct iscsi_cls_conn *conn = iscsi_dev_to_conn(dev);
 549         struct device *parent = conn->dev.parent;
 550
 551         kfree(conn);
 552         put_device(parent);
 553 }
 554
 555 static int iscsi_is_conn_dev(const struct device *dev)
 556 {
 557         return dev->release == iscsi_conn_release;
 558 }
 559
 560 static int iscsi_iter_destroy_conn_fn(struct device *dev, void *data)
 561 {
 562         if (!iscsi_is_conn_dev(dev))
 563                 return 0;
 564         return iscsi_destroy_conn(iscsi_dev_to_conn(dev));
 565 }
 566
 567 void iscsi_remove_session(struct iscsi_cls_session *session)
 568 {
 569         struct Scsi_Host *shost = iscsi_session_to_shost(session);
 570         struct iscsi_host *ihost = shost->shost_data;
 571         unsigned long flags;
 572         int err;
 573
 574         spin_lock_irqsave(&sesslock, flags);
 575         list_del(&session->sess_list);
 576         spin_unlock_irqrestore(&sesslock, flags);
 577
 578         /*
 579          * If we are blocked let commands flow again. The lld or iscsi
 580          * layer should set up the queuecommand to fail commands.
 581          */
 582         spin_lock_irqsave(&session->lock, flags);
 583         session->state = ISCSI_SESSION_FREE;
 584         spin_unlock_irqrestore(&session->lock, flags);
 585         __iscsi_unblock_session(session);
 586         __iscsi_unbind_session(&session->unbind_work);
 587
 588         /* flush running scans */
 589         flush_workqueue(ihost->scan_workq);
 590         /*
 591          * If the session dropped while removing devices then we need to make
 592          * sure it is not blocked
 593          */
 594         if (!cancel_delayed_work(&session->recovery_work))
 595                 flush_workqueue(iscsi_eh_timer_workq);
 596
 597         /* hw iscsi may not have removed all connections from session */
 598         err = device_for_each_child(&session->dev, NULL,
 599                                     iscsi_iter_destroy_conn_fn);
 600         if (err)
 601                 iscsi_cls_session_printk(KERN_ERR, session,
 602                                          "Could not delete all connections "
 603                                          "for session. Error %d.\n", err);
 604
 605         transport_unregister_device(&session->dev);
 606         device_del(&session->dev);
 607 }
 608 EXPORT_SYMBOL_GPL(iscsi_remove_session);
 609
 610 void iscsi_free_session(struct iscsi_cls_session *session)
 611 {
 612         iscsi_session_event(session, ISCSI_KEVENT_DESTROY_SESSION);
 613         put_device(&session->dev);
 614 }
 615 EXPORT_SYMBOL_GPL(iscsi_free_session);
 616
 617 /**
 618  * iscsi_destroy_session - destroy iscsi session
 619  * @session: iscsi_session
 620  *
 621  * Can be called by a LLD or iscsi_transport. There must not be
 622  * any running connections.
 623  */
 624 int iscsi_destroy_session(struct iscsi_cls_session *session)
 625 {
 626         iscsi_remove_session(session);
 627         iscsi_free_session(session);
 628         return 0;
 629 }
 630 EXPORT_SYMBOL_GPL(iscsi_destroy_session);
 631
 632 /**
 633  * iscsi_create_conn - create iscsi class connection
 634  * @session: iscsi cls session
 635  * @cid: connection id
 636  *
 637  * This can be called from a LLD or iscsi_transport. The connection
 638  * is child of the session so cid must be unique for all connections
 639  * on the session.
 640  *
 641  * Since we do not support MCS, cid will normally be zero. In some cases
 642  * for software iscsi we could be trying to preallocate a connection struct
 643  * in which case there could be two connection structs and cid would be
 644  * non-zero.
 645  */
 646 struct iscsi_cls_conn *
 647 iscsi_create_conn(struct iscsi_cls_session *session, uint32_t cid)
 648 {
 649         struct iscsi_transport *transport = session->transport;
 650         struct iscsi_cls_conn *conn;
 651         unsigned long flags;
 652         int err;
 653
 654         conn = kzalloc(sizeof(*conn) + transport->conndata_size, GFP_KERNEL);
 655         if (!conn)
 656                 return NULL;
 657
 658         if (transport->conndata_size)
 659                 conn->dd_data = &conn[1];
 660
 661         INIT_LIST_HEAD(&conn->conn_list);
 662         conn->transport = transport;
 663         conn->cid = cid;
 664
 665         /* this is released in the dev's release function */
 666         if (!get_device(&session->dev))
 667                 goto free_conn;
 668
 669         snprintf(conn->dev.bus_id, BUS_ID_SIZE, "connection%d:%u",
 670                  session->sid, cid);
 671         conn->dev.parent = &session->dev;
 672         conn->dev.release = iscsi_conn_release;
 673         err = device_register(&conn->dev);
 674         if (err) {
 675                 iscsi_cls_session_printk(KERN_ERR, session, "could not "
 676                                          "register connection's dev\n");
 677                 goto release_parent_ref;
 678         }
 679         transport_register_device(&conn->dev);
 680
 681         spin_lock_irqsave(&connlock, flags);
 682         list_add(&conn->conn_list, &connlist);
 683         conn->active = 1;
 684         spin_unlock_irqrestore(&connlock, flags);
 685         return conn;
 686
 687 release_parent_ref:
 688         put_device(&session->dev);
 689 free_conn:
 690         kfree(conn);
 691         return NULL;
 692 }
 693
 694 EXPORT_SYMBOL_GPL(iscsi_create_conn);
 695
 696 /**
 697  * iscsi_destroy_conn - destroy iscsi class connection
 698  * @conn: iscsi cls session
 699  *
 700  * This can be called from a LLD or iscsi_transport.
 701  */
 702 int iscsi_destroy_conn(struct iscsi_cls_conn *conn)
 703 {
 704         unsigned long flags;
 705
 706         spin_lock_irqsave(&connlock, flags);
 707         conn->active = 0;
 708         list_del(&conn->conn_list);
 709         spin_unlock_irqrestore(&connlock, flags);
 710
 711         transport_unregister_device(&conn->dev);
 712         device_unregister(&conn->dev);
 713         return 0;
 714 }
 715 EXPORT_SYMBOL_GPL(iscsi_destroy_conn);
 716
 717 /*
 718  * iscsi interface functions
 719  */
 720 static struct iscsi_internal *
 721 iscsi_if_transport_lookup(struct iscsi_transport *tt)
 722 {
 723         struct iscsi_internal *priv;
 724         unsigned long flags;
 725
 726         spin_lock_irqsave(&iscsi_transport_lock, flags);
 727         list_for_each_entry(priv, &iscsi_transports, list) {
 728                 if (tt == priv->iscsi_transport) {
 729                         spin_unlock_irqrestore(&iscsi_transport_lock, flags);
 730                         return priv;
 731                 }
 732         }
 733         spin_unlock_irqrestore(&iscsi_transport_lock, flags);
 734         return NULL;
 735 }
 736
 737 static int
 738 iscsi_broadcast_skb(struct sk_buff *skb, gfp_t gfp)
 739 {
 740         int rc;
 741
 742         rc = netlink_broadcast(nls, skb, 0, 1, gfp);
 743         if (rc < 0) {
 744                 printk(KERN_ERR "iscsi: can not broadcast skb (%d)\n", rc);
 745                 return rc;
 746         }
 747
 748         return 0;
 749 }
 750
 751 static int
 752 iscsi_unicast_skb(struct sk_buff *skb, int pid)
 753 {
 754         int rc;
 755
 756         rc = netlink_unicast(nls, skb, pid, MSG_DONTWAIT);
 757         if (rc < 0) {
 758                 printk(KERN_ERR "iscsi: can not unicast skb (%d)\n", rc);
 759                 return rc;
 760         }
 761
 762         return 0;
 763 }
 764
 765 int iscsi_recv_pdu(struct iscsi_cls_conn *conn, struct iscsi_hdr *hdr,
 766                    char *data, uint32_t data_size)
 767 {
 768         struct nlmsghdr *nlh;
 769         struct sk_buff *skb;
 770         struct iscsi_uevent *ev;
 771         char *pdu;
 772         struct iscsi_internal *priv;
 773         int len = NLMSG_SPACE(sizeof(*ev) + sizeof(struct iscsi_hdr) +
 774                               data_size);
 775
 776         priv = iscsi_if_transport_lookup(conn->transport);
 777         if (!priv)
 778                 return -EINVAL;
 779
 780         skb = alloc_skb(len, GFP_ATOMIC);
 781         if (!skb) {
 782                 iscsi_conn_error(conn, ISCSI_ERR_CONN_FAILED);
 783                 iscsi_cls_conn_printk(KERN_ERR, conn, "can not deliver "
 784                                       "control PDU: OOM\n");
 785                 return -ENOMEM;
 786         }
 787
 788         nlh = __nlmsg_put(skb, priv->daemon_pid, 0, 0, (len - sizeof(*nlh)), 0);
 789         ev = NLMSG_DATA(nlh);
 790         memset(ev, 0, sizeof(*ev));
 791         ev->transport_handle = iscsi_handle(conn->transport);
 792         ev->type = ISCSI_KEVENT_RECV_PDU;
 793         ev->r.recv_req.cid = conn->cid;
 794         ev->r.recv_req.sid = iscsi_conn_get_sid(conn);
 795         pdu = (char*)ev + sizeof(*ev);
 796         memcpy(pdu, hdr, sizeof(struct iscsi_hdr));
 797         memcpy(pdu + sizeof(struct iscsi_hdr), data, data_size);
 798
 799         return iscsi_unicast_skb(skb, priv->daemon_pid);
 800 }
 801 EXPORT_SYMBOL_GPL(iscsi_recv_pdu);
 802
 803 void iscsi_conn_error(struct iscsi_cls_conn *conn, enum iscsi_err error)
 804 {
 805         struct iscsi_cls_session *session = iscsi_conn_to_session(conn);
 806         struct nlmsghdr *nlh;
 807         struct sk_buff  *skb;
 808         struct iscsi_uevent *ev;
 809         struct iscsi_internal *priv;
 810         int len = NLMSG_SPACE(sizeof(*ev));
 811         unsigned long flags;
 812
 813         priv = iscsi_if_transport_lookup(conn->transport);
 814         if (!priv)
 815                 return;
 816
 817         spin_lock_irqsave(&session->lock, flags);
 818         if (session->state == ISCSI_SESSION_LOGGED_IN)
 819                 session->state = ISCSI_SESSION_FAILED;
 820         spin_unlock_irqrestore(&session->lock, flags);
 821
 822         skb = alloc_skb(len, GFP_ATOMIC);
 823         if (!skb) {
 824                 iscsi_cls_conn_printk(KERN_ERR, conn, "gracefully ignored "
 825                                       "conn error (%d)\n", error);
 826                 return;
 827         }
 828
 829         nlh = __nlmsg_put(skb, priv->daemon_pid, 0, 0, (len - sizeof(*nlh)), 0);
 830         ev = NLMSG_DATA(nlh);
 831         ev->transport_handle = iscsi_handle(conn->transport);
 832         ev->type = ISCSI_KEVENT_CONN_ERROR;
 833         ev->r.connerror.error = error;
 834         ev->r.connerror.cid = conn->cid;
 835         ev->r.connerror.sid = iscsi_conn_get_sid(conn);
 836
 837         iscsi_broadcast_skb(skb, GFP_ATOMIC);
 838
 839         iscsi_cls_conn_printk(KERN_INFO, conn, "detected conn error (%d)\n",
 840                               error);
 841 }
 842 EXPORT_SYMBOL_GPL(iscsi_conn_error);
 843
 844 static int
 845 iscsi_if_send_reply(int pid, int seq, int type, int done, int multi,
 846                       void *payload, int size)
 847 {
 848         struct sk_buff  *skb;
 849         struct nlmsghdr *nlh;
 850         int len = NLMSG_SPACE(size);
 851         int flags = multi ? NLM_F_MULTI : 0;
 852         int t = done ? NLMSG_DONE : type;
 853
 854         skb = alloc_skb(len, GFP_ATOMIC);
 855         if (!skb) {
 856                 printk(KERN_ERR "Could not allocate skb to send reply.\n");
 857                 return -ENOMEM;
 858         }
 859
 860         nlh = __nlmsg_put(skb, pid, seq, t, (len - sizeof(*nlh)), 0);
 861         nlh->nlmsg_flags = flags;
 862         memcpy(NLMSG_DATA(nlh), payload, size);
 863         return iscsi_unicast_skb(skb, pid);
 864 }
 865
 866 static int
 867 iscsi_if_get_stats(struct iscsi_transport *transport, struct nlmsghdr *nlh)
 868 {
 869         struct iscsi_uevent *ev = NLMSG_DATA(nlh);
 870         struct iscsi_stats *stats;
 871         struct sk_buff *skbstat;
 872         struct iscsi_cls_conn *conn;
 873         struct nlmsghdr *nlhstat;
 874         struct iscsi_uevent *evstat;
 875         struct iscsi_internal *priv;
 876         int len = NLMSG_SPACE(sizeof(*ev) +
 877                               sizeof(struct iscsi_stats) +
 878                               sizeof(struct iscsi_stats_custom) *
 879                               ISCSI_STATS_CUSTOM_MAX);
 880         int err = 0;
 881
 882         priv = iscsi_if_transport_lookup(transport);
 883         if (!priv)
 884                 return -EINVAL;
 885
 886         conn = iscsi_conn_lookup(ev->u.get_stats.sid, ev->u.get_stats.cid);
 887         if (!conn)
 888                 return -EEXIST;
 889
 890         do {
 891                 int actual_size;
 892
 893                 skbstat = alloc_skb(len, GFP_ATOMIC);
 894                 if (!skbstat) {
 895                         iscsi_cls_conn_printk(KERN_ERR, conn, "can not "
 896                                               "deliver stats: OOM\n");
 897                         return -ENOMEM;
 898                 }
 899
 900                 nlhstat = __nlmsg_put(skbstat, priv->daemon_pid, 0, 0,
 901                                       (len - sizeof(*nlhstat)), 0);
 902                 evstat = NLMSG_DATA(nlhstat);
 903                 memset(evstat, 0, sizeof(*evstat));
 904                 evstat->transport_handle = iscsi_handle(conn->transport);
 905                 evstat->type = nlh->nlmsg_type;
 906                 evstat->u.get_stats.cid =
 907                         ev->u.get_stats.cid;
 908                 evstat->u.get_stats.sid =
 909                         ev->u.get_stats.sid;
 910                 stats = (struct iscsi_stats *)
 911                         ((char*)evstat + sizeof(*evstat));
 912                 memset(stats, 0, sizeof(*stats));
 913
 914                 transport->get_stats(conn, stats);
 915                 actual_size = NLMSG_SPACE(sizeof(struct iscsi_uevent) +
 916                                           sizeof(struct iscsi_stats) +
 917                                           sizeof(struct iscsi_stats_custom) *
 918                                           stats->custom_length);
 919                 actual_size -= sizeof(*nlhstat);
 920                 actual_size = NLMSG_LENGTH(actual_size);
 921                 skb_trim(skbstat, NLMSG_ALIGN(actual_size));
 922                 nlhstat->nlmsg_len = actual_size;
 923
 924                 err = iscsi_unicast_skb(skbstat, priv->daemon_pid);
 925         } while (err < 0 && err != -ECONNREFUSED);
 926
 927         return err;
 928 }
 929
 930 /**
 931  * iscsi_session_event - send session destr. completion event
 932  * @session: iscsi class session
 933  * @event: type of event
 934  */
 935 int iscsi_session_event(struct iscsi_cls_session *session,
 936                         enum iscsi_uevent_e event)
 937 {
 938         struct iscsi_internal *priv;
 939         struct Scsi_Host *shost;
 940         struct iscsi_uevent *ev;
 941         struct sk_buff  *skb;
 942         struct nlmsghdr *nlh;
 943         int rc, len = NLMSG_SPACE(sizeof(*ev));
 944
 945         priv = iscsi_if_transport_lookup(session->transport);
 946         if (!priv)
 947                 return -EINVAL;
 948         shost = iscsi_session_to_shost(session);
 949
 950         skb = alloc_skb(len, GFP_KERNEL);
 951         if (!skb) {
 952                 iscsi_cls_session_printk(KERN_ERR, session,
 953                                          "Cannot notify userspace of session "
 954                                          "event %u\n", event);
 955                 return -ENOMEM;
 956         }
 957
 958         nlh = __nlmsg_put(skb, priv->daemon_pid, 0, 0, (len - sizeof(*nlh)), 0);
 959         ev = NLMSG_DATA(nlh);
 960         ev->transport_handle = iscsi_handle(session->transport);
 961
 962         ev->type = event;
 963         switch (event) {
 964         case ISCSI_KEVENT_DESTROY_SESSION:
 965                 ev->r.d_session.host_no = shost->host_no;
 966                 ev->r.d_session.sid = session->sid;
 967                 break;
 968         case ISCSI_KEVENT_CREATE_SESSION:
 969                 ev->r.c_session_ret.host_no = shost->host_no;
 970                 ev->r.c_session_ret.sid = session->sid;
 971                 break;
 972         case ISCSI_KEVENT_UNBIND_SESSION:
 973                 ev->r.unbind_session.host_no = shost->host_no;
 974                 ev->r.unbind_session.sid = session->sid;
 975                 break;
 976         default:
 977                 iscsi_cls_session_printk(KERN_ERR, session, "Invalid event "
 978                                          "%u.\n", event);
 979                 kfree_skb(skb);
 980                 return -EINVAL;
 981         }
 982
 983         /*
 984          * this will occur if the daemon is not up, so we just warn
 985          * the user and when the daemon is restarted it will handle it
 986          */
 987         rc = iscsi_broadcast_skb(skb, GFP_KERNEL);
 988         if (rc < 0)
 989                 iscsi_cls_session_printk(KERN_ERR, session,
 990                                          "Cannot notify userspace of session "
 991                                          "event %u. Check iscsi daemon\n",
 992                                          event);
 993         return rc;
 994 }
 995 EXPORT_SYMBOL_GPL(iscsi_session_event);
 996
 997 static int
 998 iscsi_if_create_session(struct iscsi_internal *priv, struct iscsi_uevent *ev)
 999 {
1000         struct iscsi_transport *transport = priv->iscsi_transport;
1001         struct iscsi_cls_session *session;
1002         uint32_t hostno;
1003
1004         session = transport->create_session(transport, &priv->t,
1005                                             ev->u.c_session.cmds_max,
1006                                             ev->u.c_session.queue_depth,
1007                                             ev->u.c_session.initial_cmdsn,
1008                                             &hostno);
1009         if (!session)
1010                 return -ENOMEM;
1011
1012         ev->r.c_session_ret.host_no = hostno;
1013         ev->r.c_session_ret.sid = session->sid;
1014         return 0;
1015 }
1016
1017 static int
1018 iscsi_if_create_conn(struct iscsi_transport *transport, struct iscsi_uevent *ev)
1019 {
1020         struct iscsi_cls_conn *conn;
1021         struct iscsi_cls_session *session;
1022
1023         session = iscsi_session_lookup(ev->u.c_conn.sid);
1024         if (!session) {
1025                 printk(KERN_ERR "iscsi: invalid session %d.\n",
1026                        ev->u.c_conn.sid);
1027                 return -EINVAL;
1028         }
1029
1030         conn = transport->create_conn(session, ev->u.c_conn.cid);
1031         if (!conn) {
1032                 iscsi_cls_session_printk(KERN_ERR, session,
1033                                          "couldn't create a new connection.");
1034                 return -ENOMEM;
1035         }
1036
1037         ev->r.c_conn_ret.sid = session->sid;
1038         ev->r.c_conn_ret.cid = conn->cid;
1039         return 0;
1040 }
1041
1042 static int
1043 iscsi_if_destroy_conn(struct iscsi_transport *transport, struct iscsi_uevent *ev)
1044 {
1045         struct iscsi_cls_conn *conn;
1046
1047         conn = iscsi_conn_lookup(ev->u.d_conn.sid, ev->u.d_conn.cid);
1048         if (!conn)
1049                 return -EINVAL;
1050
1051         if (transport->destroy_conn)
1052                 transport->destroy_conn(conn);
1053         return 0;
1054 }
1055
1056 static int
1057 iscsi_set_param(struct iscsi_transport *transport, struct iscsi_uevent *ev)
1058 {
1059         char *data = (char*)ev + sizeof(*ev);
1060         struct iscsi_cls_conn *conn;
1061         struct iscsi_cls_session *session;
1062         int err = 0, value = 0;
1063
1064         session = iscsi_session_lookup(ev->u.set_param.sid);
1065         conn = iscsi_conn_lookup(ev->u.set_param.sid, ev->u.set_param.cid);
1066         if (!conn || !session)
1067                 return -EINVAL;
1068
1069         switch (ev->u.set_param.param) {
1070         case ISCSI_PARAM_SESS_RECOVERY_TMO:
1071                 sscanf(data, "%d", &value);
1072                 if (value != 0)
1073                         session->recovery_tmo = value;
1074                 break;
1075         default:
1076                 err = transport->set_param(conn, ev->u.set_param.param,
1077                                            data, ev->u.set_param.len);
1078         }
1079
1080         return err;
1081 }
1082
1083 static int
1084 iscsi_if_transport_ep(struct iscsi_transport *transport,
1085                       struct iscsi_uevent *ev, int msg_type)
1086 {
1087         struct sockaddr *dst_addr;
1088         int rc = 0;
1089
1090         switch (msg_type) {
1091         case ISCSI_UEVENT_TRANSPORT_EP_CONNECT:
1092                 if (!transport->ep_connect)
1093                         return -EINVAL;
1094
1095                 dst_addr = (struct sockaddr *)((char*)ev + sizeof(*ev));
1096                 rc = transport->ep_connect(dst_addr,
1097                                            ev->u.ep_connect.non_blocking,
1098                                            &ev->r.ep_connect_ret.handle);
1099                 break;
1100         case ISCSI_UEVENT_TRANSPORT_EP_POLL:
1101                 if (!transport->ep_poll)
1102                         return -EINVAL;
1103
1104                 ev->r.retcode = transport->ep_poll(ev->u.ep_poll.ep_handle,
1105                                                    ev->u.ep_poll.timeout_ms);
1106                 break;
1107         case ISCSI_UEVENT_TRANSPORT_EP_DISCONNECT:
1108                 if (!transport->ep_disconnect)
1109                         return -EINVAL;
1110
1111                 transport->ep_disconnect(ev->u.ep_disconnect.ep_handle);
1112                 break;
1113         }
1114         return rc;
1115 }
1116
1117 static int
1118 iscsi_tgt_dscvr(struct iscsi_transport *transport,
1119                 struct iscsi_uevent *ev)
1120 {
1121         struct Scsi_Host *shost;
1122         struct sockaddr *dst_addr;
1123         int err;
1124
1125         if (!transport->tgt_dscvr)
1126                 return -EINVAL;
1127
1128         shost = scsi_host_lookup(ev->u.tgt_dscvr.host_no);
1129         if (IS_ERR(shost)) {
1130                 printk(KERN_ERR "target discovery could not find host no %u\n",
1131                        ev->u.tgt_dscvr.host_no);
1132                 return -ENODEV;
1133         }
1134
1135
1136         dst_addr = (struct sockaddr *)((char*)ev + sizeof(*ev));
1137         err = transport->tgt_dscvr(shost, ev->u.tgt_dscvr.type,
1138                                    ev->u.tgt_dscvr.enable, dst_addr);
1139         scsi_host_put(shost);
1140         return err;
1141 }
1142
1143 static int
1144 iscsi_set_host_param(struct iscsi_transport *transport,
1145                      struct iscsi_uevent *ev)
1146 {
1147         char *data = (char*)ev + sizeof(*ev);
1148         struct Scsi_Host *shost;
1149         int err;
1150
1151         if (!transport->set_host_param)
1152                 return -ENOSYS;
1153
1154         shost = scsi_host_lookup(ev->u.set_host_param.host_no);
1155         if (IS_ERR(shost)) {
1156                 printk(KERN_ERR "set_host_param could not find host no %u\n",
1157                        ev->u.set_host_param.host_no);
1158                 return -ENODEV;
1159         }
1160
1161         err = transport->set_host_param(shost, ev->u.set_host_param.param,
1162                                         data, ev->u.set_host_param.len);
1163         scsi_host_put(shost);
1164         return err;
1165 }
1166
1167 static int
1168 iscsi_if_recv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
1169 {
1170         int err = 0;
1171         struct iscsi_uevent *ev = NLMSG_DATA(nlh);
1172         struct iscsi_transport *transport = NULL;
1173         struct iscsi_internal *priv;
1174         struct iscsi_cls_session *session;
1175         struct iscsi_cls_conn *conn;
1176
1177         priv = iscsi_if_transport_lookup(iscsi_ptr(ev->transport_handle));
1178         if (!priv)
1179                 return -EINVAL;
1180         transport = priv->iscsi_transport;
1181
1182         if (!try_module_get(transport->owner))
1183                 return -EINVAL;
1184
1185         priv->daemon_pid = NETLINK_CREDS(skb)->pid;
1186
1187         switch (nlh->nlmsg_type) {
1188         case ISCSI_UEVENT_CREATE_SESSION:
1189                 err = iscsi_if_create_session(priv, ev);
1190                 break;
1191         case ISCSI_UEVENT_DESTROY_SESSION:
1192                 session = iscsi_session_lookup(ev->u.d_session.sid);
1193                 if (session)
1194                         transport->destroy_session(session);
1195                 else
1196                         err = -EINVAL;
1197                 break;
1198         case ISCSI_UEVENT_UNBIND_SESSION:
1199                 session = iscsi_session_lookup(ev->u.d_session.sid);
1200                 if (session)
1201                         iscsi_unbind_session(session);
1202                 else
1203                         err = -EINVAL;
1204                 break;
1205         case ISCSI_UEVENT_CREATE_CONN:
1206                 err = iscsi_if_create_conn(transport, ev);
1207                 break;
1208         case ISCSI_UEVENT_DESTROY_CONN:
1209                 err = iscsi_if_destroy_conn(transport, ev);
1210                 break;
1211         case ISCSI_UEVENT_BIND_CONN:
1212                 session = iscsi_session_lookup(ev->u.b_conn.sid);
1213                 conn = iscsi_conn_lookup(ev->u.b_conn.sid, ev->u.b_conn.cid);
1214
1215                 if (session && conn)
1216                         ev->r.retcode = transport->bind_conn(session, conn,
1217                                         ev->u.b_conn.transport_eph,
1218                                         ev->u.b_conn.is_leading);
1219                 else
1220                         err = -EINVAL;
1221                 break;
1222         case ISCSI_UEVENT_SET_PARAM:
1223                 err = iscsi_set_param(transport, ev);
1224                 break;
1225         case ISCSI_UEVENT_START_CONN:
1226                 conn = iscsi_conn_lookup(ev->u.start_conn.sid, ev->u.start_conn.cid);
1227                 if (conn)
1228                         ev->r.retcode = transport->start_conn(conn);
1229                 else
1230                         err = -EINVAL;
1231                 break;
1232         case ISCSI_UEVENT_STOP_CONN:
1233                 conn = iscsi_conn_lookup(ev->u.stop_conn.sid, ev->u.stop_conn.cid);
1234                 if (conn)
1235                         transport->stop_conn(conn, ev->u.stop_conn.flag);
1236                 else
1237                         err = -EINVAL;
1238                 break;
1239         case ISCSI_UEVENT_SEND_PDU:
1240                 conn = iscsi_conn_lookup(ev->u.send_pdu.sid, ev->u.send_pdu.cid);
1241                 if (conn)
1242                         ev->r.retcode = transport->send_pdu(conn,
1243                                 (struct iscsi_hdr*)((char*)ev + sizeof(*ev)),
1244                                 (char*)ev + sizeof(*ev) + ev->u.send_pdu.hdr_size,
1245                                 ev->u.send_pdu.data_size);
1246                 else
1247                         err = -EINVAL;
1248                 break;
1249         case ISCSI_UEVENT_GET_STATS:
1250                 err = iscsi_if_get_stats(transport, nlh);
1251                 break;
1252         case ISCSI_UEVENT_TRANSPORT_EP_CONNECT:
1253         case ISCSI_UEVENT_TRANSPORT_EP_POLL:
1254         case ISCSI_UEVENT_TRANSPORT_EP_DISCONNECT:
1255                 err = iscsi_if_transport_ep(transport, ev, nlh->nlmsg_type);
1256                 break;
1257         case ISCSI_UEVENT_TGT_DSCVR:
1258                 err = iscsi_tgt_dscvr(transport, ev);
1259                 break;
1260         case ISCSI_UEVENT_SET_HOST_PARAM:
1261                 err = iscsi_set_host_param(transport, ev);
1262                 break;
1263         default:
1264                 err = -ENOSYS;
1265                 break;
1266         }
1267
1268         module_put(transport->owner);
1269         return err;
1270 }
1271
1272 /*
1273  * Get message from skb.  Each message is processed by iscsi_if_recv_msg.
1274  * Malformed skbs with wrong lengths or invalid creds are not processed.
1275  */
1276 static void
1277 iscsi_if_rx(struct sk_buff *skb)
1278 {
1279         mutex_lock(&rx_queue_mutex);
1280         while (skb->len >= NLMSG_SPACE(0)) {
1281                 int err;
1282                 uint32_t rlen;
1283                 struct nlmsghdr *nlh;
1284                 struct iscsi_uevent *ev;
1285
1286                 nlh = nlmsg_hdr(skb);
1287                 if (nlh->nlmsg_len < sizeof(*nlh) ||
1288                     skb->len < nlh->nlmsg_len) {
1289                         break;
1290                 }
1291
1292                 ev = NLMSG_DATA(nlh);
1293                 rlen = NLMSG_ALIGN(nlh->nlmsg_len);
1294                 if (rlen > skb->len)
1295                         rlen = skb->len;
1296
1297                 err = iscsi_if_recv_msg(skb, nlh);
1298                 if (err) {
1299                         ev->type = ISCSI_KEVENT_IF_ERROR;
1300                         ev->iferror = err;
1301                 }
1302                 do {
1303                         /*
1304                          * special case for GET_STATS:
1305                          * on success - sending reply and stats from
1306                          * inside of if_recv_msg(),
1307                          * on error - fall through.
1308                          */
1309                         if (ev->type == ISCSI_UEVENT_GET_STATS && !err)
1310                                 break;
1311                         err = iscsi_if_send_reply(
1312                                 NETLINK_CREDS(skb)->pid, nlh->nlmsg_seq,
1313                                 nlh->nlmsg_type, 0, 0, ev, sizeof(*ev));
1314                 } while (err < 0 && err != -ECONNREFUSED);
1315                 skb_pull(skb, rlen);
1316         }
1317         mutex_unlock(&rx_queue_mutex);
1318 }
1319
1320 #define iscsi_cdev_to_conn(_cdev) \
1321         iscsi_dev_to_conn(_cdev->dev)
1322
1323 #define ISCSI_CLASS_ATTR(_prefix,_name,_mode,_show,_store)              \
1324 struct class_device_attribute class_device_attr_##_prefix##_##_name =   \
1325         __ATTR(_name,_mode,_show,_store)
1326
1327 /*
1328  * iSCSI connection attrs
1329  */
1330 #define iscsi_conn_attr_show(param)                                     \
1331 static ssize_t                                                          \
1332 show_conn_param_##param(struct class_device *cdev, char *buf)           \
1333 {                                                                       \
1334         struct iscsi_cls_conn *conn = iscsi_cdev_to_conn(cdev);         \
1335         struct iscsi_transport *t = conn->transport;                    \
1336         return t->get_conn_param(conn, param, buf);                     \
1337 }
1338
1339 #define iscsi_conn_attr(field, param)                                   \
1340         iscsi_conn_attr_show(param)                                     \
1341 static ISCSI_CLASS_ATTR(conn, field, S_IRUGO, show_conn_param_##param,  \
1342                         NULL);
1343
1344 iscsi_conn_attr(max_recv_dlength, ISCSI_PARAM_MAX_RECV_DLENGTH);
1345 iscsi_conn_attr(max_xmit_dlength, ISCSI_PARAM_MAX_XMIT_DLENGTH);
1346 iscsi_conn_attr(header_digest, ISCSI_PARAM_HDRDGST_EN);
1347 iscsi_conn_attr(data_digest, ISCSI_PARAM_DATADGST_EN);
1348 iscsi_conn_attr(ifmarker, ISCSI_PARAM_IFMARKER_EN);
1349 iscsi_conn_attr(ofmarker, ISCSI_PARAM_OFMARKER_EN);
1350 iscsi_conn_attr(persistent_port, ISCSI_PARAM_PERSISTENT_PORT);
1351 iscsi_conn_attr(port, ISCSI_PARAM_CONN_PORT);
1352 iscsi_conn_attr(exp_statsn, ISCSI_PARAM_EXP_STATSN);
1353 iscsi_conn_attr(persistent_address, ISCSI_PARAM_PERSISTENT_ADDRESS);
1354 iscsi_conn_attr(address, ISCSI_PARAM_CONN_ADDRESS);
1355 iscsi_conn_attr(ping_tmo, ISCSI_PARAM_PING_TMO);
1356 iscsi_conn_attr(recv_tmo, ISCSI_PARAM_RECV_TMO);
1357
1358 #define iscsi_cdev_to_session(_cdev) \
1359         iscsi_dev_to_session(_cdev->dev)
1360
1361 /*
1362  * iSCSI session attrs
1363  */
1364 #define iscsi_session_attr_show(param, perm)                            \
1365 static ssize_t                                                          \
1366 show_session_param_##param(struct class_device *cdev, char *buf)        \
1367 {                                                                       \
1368         struct iscsi_cls_session *session = iscsi_cdev_to_session(cdev); \
1369         struct iscsi_transport *t = session->transport;                 \
1370                                                                         \
1371         if (perm && !capable(CAP_SYS_ADMIN))                            \
1372                 return -EACCES;                                         \
1373         return t->get_session_param(session, param, buf);               \
1374 }
1375
1376 #define iscsi_session_attr(field, param, perm)                          \
1377         iscsi_session_attr_show(param, perm)                            \
1378 static ISCSI_CLASS_ATTR(sess, field, S_IRUGO, show_session_param_##param, \
1379                         NULL);
1380
1381 iscsi_session_attr(targetname, ISCSI_PARAM_TARGET_NAME, 0);
1382 iscsi_session_attr(initial_r2t, ISCSI_PARAM_INITIAL_R2T_EN, 0);
1383 iscsi_session_attr(max_outstanding_r2t, ISCSI_PARAM_MAX_R2T, 0);
1384 iscsi_session_attr(immediate_data, ISCSI_PARAM_IMM_DATA_EN, 0);
1385 iscsi_session_attr(first_burst_len, ISCSI_PARAM_FIRST_BURST, 0);
1386 iscsi_session_attr(max_burst_len, ISCSI_PARAM_MAX_BURST, 0);
1387 iscsi_session_attr(data_pdu_in_order, ISCSI_PARAM_PDU_INORDER_EN, 0);
1388 iscsi_session_attr(data_seq_in_order, ISCSI_PARAM_DATASEQ_INORDER_EN, 0);
1389 iscsi_session_attr(erl, ISCSI_PARAM_ERL, 0);
1390 iscsi_session_attr(tpgt, ISCSI_PARAM_TPGT, 0);
1391 iscsi_session_attr(username, ISCSI_PARAM_USERNAME, 1);
1392 iscsi_session_attr(username_in, ISCSI_PARAM_USERNAME_IN, 1);
1393 iscsi_session_attr(password, ISCSI_PARAM_PASSWORD, 1);
1394 iscsi_session_attr(password_in, ISCSI_PARAM_PASSWORD_IN, 1);
1395 iscsi_session_attr(fast_abort, ISCSI_PARAM_FAST_ABORT, 0);
1396 iscsi_session_attr(abort_tmo, ISCSI_PARAM_ABORT_TMO, 0);
1397 iscsi_session_attr(lu_reset_tmo, ISCSI_PARAM_LU_RESET_TMO, 0);
1398
1399 static ssize_t
1400 show_priv_session_state(struct class_device *cdev, char *buf)
1401 {
1402         struct iscsi_cls_session *session = iscsi_cdev_to_session(cdev);
1403         return sprintf(buf, "%s\n", iscsi_session_state_name(session->state));
1404 }
1405 static ISCSI_CLASS_ATTR(priv_sess, state, S_IRUGO, show_priv_session_state,
1406                         NULL);
1407
1408 #define iscsi_priv_session_attr_show(field, format)                     \
1409 static ssize_t                                                          \
1410 show_priv_session_##field(struct class_device *cdev, char *buf)         \
1411 {                                                                       \
1412         struct iscsi_cls_session *session = iscsi_cdev_to_session(cdev);\
1413         return sprintf(buf, format"\n", session->field);                \
1414 }
1415
1416 #define iscsi_priv_session_attr(field, format)                          \
1417         iscsi_priv_session_attr_show(field, format)                     \
1418 static ISCSI_CLASS_ATTR(priv_sess, field, S_IRUGO, show_priv_session_##field, \
1419                         NULL)
1420 iscsi_priv_session_attr(recovery_tmo, "%d");
1421
1422 /*
1423  * iSCSI host attrs
1424  */
1425 #define iscsi_host_attr_show(param)                                     \
1426 static ssize_t                                                          \
1427 show_host_param_##param(struct class_device *cdev, char *buf)           \
1428 {                                                                       \
1429         struct Scsi_Host *shost = transport_class_to_shost(cdev);       \
1430         struct iscsi_internal *priv = to_iscsi_internal(shost->transportt); \
1431         return priv->iscsi_transport->get_host_param(shost, param, buf); \
1432 }
1433
1434 #define iscsi_host_attr(field, param)                                   \
1435         iscsi_host_attr_show(param)                                     \
1436 static ISCSI_CLASS_ATTR(host, field, S_IRUGO, show_host_param_##param,  \
1437                         NULL);
1438
1439 iscsi_host_attr(netdev, ISCSI_HOST_PARAM_NETDEV_NAME);
1440 iscsi_host_attr(hwaddress, ISCSI_HOST_PARAM_HWADDRESS);
1441 iscsi_host_attr(ipaddress, ISCSI_HOST_PARAM_IPADDRESS);
1442 iscsi_host_attr(initiatorname, ISCSI_HOST_PARAM_INITIATOR_NAME);
1443
1444 #define SETUP_PRIV_SESSION_RD_ATTR(field)                               \
1445 do {                                                                    \
1446         priv->session_attrs[count] = &class_device_attr_priv_sess_##field; \
1447         count++;                                                        \
1448 } while (0)
1449
1450
1451 #define SETUP_SESSION_RD_ATTR(field, param_flag)                        \
1452 do {                                                                    \
1453         if (tt->param_mask & param_flag) {                              \
1454                 priv->session_attrs[count] = &class_device_attr_sess_##field; \
1455                 count++;                                                \
1456         }                                                               \
1457 } while (0)
1458
1459 #define SETUP_CONN_RD_ATTR(field, param_flag)                           \
1460 do {                                                                    \
1461         if (tt->param_mask & param_flag) {                              \
1462                 priv->conn_attrs[count] = &class_device_attr_conn_##field; \
1463                 count++;                                                \
1464         }                                                               \
1465 } while (0)
1466
1467 #define SETUP_HOST_RD_ATTR(field, param_flag)                           \
1468 do {                                                                    \
1469         if (tt->host_param_mask & param_flag) {                         \
1470                 priv->host_attrs[count] = &class_device_attr_host_##field; \
1471                 count++;                                                \
1472         }                                                               \
1473 } while (0)
1474
1475 static int iscsi_session_match(struct attribute_container *cont,
1476                            struct device *dev)
1477 {
1478         struct iscsi_cls_session *session;
1479         struct Scsi_Host *shost;
1480         struct iscsi_internal *priv;
1481
1482         if (!iscsi_is_session_dev(dev))
1483                 return 0;
1484
1485         session = iscsi_dev_to_session(dev);
1486         shost = iscsi_session_to_shost(session);
1487         if (!shost->transportt)
1488                 return 0;
1489
1490         priv = to_iscsi_internal(shost->transportt);
1491         if (priv->session_cont.ac.class != &iscsi_session_class.class)
1492                 return 0;
1493
1494         return &priv->session_cont.ac == cont;
1495 }
1496
1497 static int iscsi_conn_match(struct attribute_container *cont,
1498                            struct device *dev)
1499 {
1500         struct iscsi_cls_session *session;
1501         struct iscsi_cls_conn *conn;
1502         struct Scsi_Host *shost;
1503         struct iscsi_internal *priv;
1504
1505         if (!iscsi_is_conn_dev(dev))
1506                 return 0;
1507
1508         conn = iscsi_dev_to_conn(dev);
1509         session = iscsi_dev_to_session(conn->dev.parent);
1510         shost = iscsi_session_to_shost(session);
1511
1512         if (!shost->transportt)
1513                 return 0;
1514
1515         priv = to_iscsi_internal(shost->transportt);
1516         if (priv->conn_cont.ac.class != &iscsi_connection_class.class)
1517                 return 0;
1518
1519         return &priv->conn_cont.ac == cont;
1520 }
1521
1522 static int iscsi_host_match(struct attribute_container *cont,
1523                             struct device *dev)
1524 {
1525         struct Scsi_Host *shost;
1526         struct iscsi_internal *priv;
1527
1528         if (!scsi_is_host_device(dev))
1529                 return 0;
1530
1531         shost = dev_to_shost(dev);
1532         if (!shost->transportt  ||
1533             shost->transportt->host_attrs.ac.class != &iscsi_host_class.class)
1534                 return 0;
1535
1536         priv = to_iscsi_internal(shost->transportt);
1537         return &priv->t.host_attrs.ac == cont;
1538 }
1539
1540 struct scsi_transport_template *
1541 iscsi_register_transport(struct iscsi_transport *tt)
1542 {
1543         struct iscsi_internal *priv;
1544         unsigned long flags;
1545         int count = 0, err;
1546
1547         BUG_ON(!tt);
1548
1549         priv = iscsi_if_transport_lookup(tt);
1550         if (priv)
1551                 return NULL;
1552
1553         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
1554         if (!priv)
1555                 return NULL;
1556         INIT_LIST_HEAD(&priv->list);
1557         priv->daemon_pid = -1;
1558         priv->iscsi_transport = tt;
1559         priv->t.user_scan = iscsi_user_scan;
1560
1561         priv->cdev.class = &iscsi_transport_class;
1562         snprintf(priv->cdev.class_id, BUS_ID_SIZE, "%s", tt->name);
1563         err = class_device_register(&priv->cdev);
1564         if (err)
1565                 goto free_priv;
1566
1567         err = sysfs_create_group(&priv->cdev.kobj, &iscsi_transport_group);
1568         if (err)
1569                 goto unregister_cdev;
1570
1571         /* host parameters */
1572         priv->t.host_attrs.ac.attrs = &priv->host_attrs[0];
1573         priv->t.host_attrs.ac.class = &iscsi_host_class.class;
1574         priv->t.host_attrs.ac.match = iscsi_host_match;
1575         priv->t.host_size = sizeof(struct iscsi_host);
1576         transport_container_register(&priv->t.host_attrs);
1577
1578         SETUP_HOST_RD_ATTR(netdev, ISCSI_HOST_NETDEV_NAME);
1579         SETUP_HOST_RD_ATTR(ipaddress, ISCSI_HOST_IPADDRESS);
1580         SETUP_HOST_RD_ATTR(hwaddress, ISCSI_HOST_HWADDRESS);
1581         SETUP_HOST_RD_ATTR(initiatorname, ISCSI_HOST_INITIATOR_NAME);
1582         BUG_ON(count > ISCSI_HOST_ATTRS);
1583         priv->host_attrs[count] = NULL;
1584         count = 0;
1585
1586         /* connection parameters */
1587         priv->conn_cont.ac.attrs = &priv->conn_attrs[0];
1588         priv->conn_cont.ac.class = &iscsi_connection_class.class;
1589         priv->conn_cont.ac.match = iscsi_conn_match;
1590         transport_container_register(&priv->conn_cont);
1591
1592         SETUP_CONN_RD_ATTR(max_recv_dlength, ISCSI_MAX_RECV_DLENGTH);
1593         SETUP_CONN_RD_ATTR(max_xmit_dlength, ISCSI_MAX_XMIT_DLENGTH);
1594         SETUP_CONN_RD_ATTR(header_digest, ISCSI_HDRDGST_EN);
1595         SETUP_CONN_RD_ATTR(data_digest, ISCSI_DATADGST_EN);
1596         SETUP_CONN_RD_ATTR(ifmarker, ISCSI_IFMARKER_EN);
1597         SETUP_CONN_RD_ATTR(ofmarker, ISCSI_OFMARKER_EN);
1598         SETUP_CONN_RD_ATTR(address, ISCSI_CONN_ADDRESS);
1599         SETUP_CONN_RD_ATTR(port, ISCSI_CONN_PORT);
1600         SETUP_CONN_RD_ATTR(exp_statsn, ISCSI_EXP_STATSN);
1601         SETUP_CONN_RD_ATTR(persistent_address, ISCSI_PERSISTENT_ADDRESS);
1602         SETUP_CONN_RD_ATTR(persistent_port, ISCSI_PERSISTENT_PORT);
1603         SETUP_CONN_RD_ATTR(ping_tmo, ISCSI_PING_TMO);
1604         SETUP_CONN_RD_ATTR(recv_tmo, ISCSI_RECV_TMO);
1605
1606         BUG_ON(count > ISCSI_CONN_ATTRS);
1607         priv->conn_attrs[count] = NULL;
1608         count = 0;
1609
1610         /* session parameters */
1611         priv->session_cont.ac.attrs = &priv->session_attrs[0];
1612         priv->session_cont.ac.class = &iscsi_session_class.class;
1613         priv->session_cont.ac.match = iscsi_session_match;
1614         transport_container_register(&priv->session_cont);
1615
1616         SETUP_SESSION_RD_ATTR(initial_r2t, ISCSI_INITIAL_R2T_EN);
1617         SETUP_SESSION_RD_ATTR(max_outstanding_r2t, ISCSI_MAX_R2T);
1618         SETUP_SESSION_RD_ATTR(immediate_data, ISCSI_IMM_DATA_EN);
1619         SETUP_SESSION_RD_ATTR(first_burst_len, ISCSI_FIRST_BURST);
1620         SETUP_SESSION_RD_ATTR(max_burst_len, ISCSI_MAX_BURST);
1621         SETUP_SESSION_RD_ATTR(data_pdu_in_order, ISCSI_PDU_INORDER_EN);
1622         SETUP_SESSION_RD_ATTR(data_seq_in_order, ISCSI_DATASEQ_INORDER_EN);
1623         SETUP_SESSION_RD_ATTR(erl, ISCSI_ERL);
1624         SETUP_SESSION_RD_ATTR(targetname, ISCSI_TARGET_NAME);
1625         SETUP_SESSION_RD_ATTR(tpgt, ISCSI_TPGT);
1626         SETUP_SESSION_RD_ATTR(password, ISCSI_USERNAME);
1627         SETUP_SESSION_RD_ATTR(password_in, ISCSI_USERNAME_IN);
1628         SETUP_SESSION_RD_ATTR(username, ISCSI_PASSWORD);
1629         SETUP_SESSION_RD_ATTR(username_in, ISCSI_PASSWORD_IN);
1630         SETUP_SESSION_RD_ATTR(fast_abort, ISCSI_FAST_ABORT);
1631         SETUP_SESSION_RD_ATTR(abort_tmo, ISCSI_ABORT_TMO);
1632         SETUP_SESSION_RD_ATTR(lu_reset_tmo,ISCSI_LU_RESET_TMO);
1633         SETUP_PRIV_SESSION_RD_ATTR(recovery_tmo);
1634         SETUP_PRIV_SESSION_RD_ATTR(state);
1635
1636         BUG_ON(count > ISCSI_SESSION_ATTRS);
1637         priv->session_attrs[count] = NULL;
1638
1639         spin_lock_irqsave(&iscsi_transport_lock, flags);
1640         list_add(&priv->list, &iscsi_transports);
1641         spin_unlock_irqrestore(&iscsi_transport_lock, flags);
1642
1643         printk(KERN_NOTICE "iscsi: registered transport (%s)\n", tt->name);
1644         return &priv->t;
1645
1646 unregister_cdev:
1647         class_device_unregister(&priv->cdev);
1648 free_priv:
1649         kfree(priv);
1650         return NULL;
1651 }
1652 EXPORT_SYMBOL_GPL(iscsi_register_transport);
1653
1654 int iscsi_unregister_transport(struct iscsi_transport *tt)
1655 {
1656         struct iscsi_internal *priv;
1657         unsigned long flags;
1658
1659         BUG_ON(!tt);
1660
1661         mutex_lock(&rx_queue_mutex);
1662
1663         priv = iscsi_if_transport_lookup(tt);
1664         BUG_ON (!priv);
1665
1666         spin_lock_irqsave(&iscsi_transport_lock, flags);
1667         list_del(&priv->list);
1668         spin_unlock_irqrestore(&iscsi_transport_lock, flags);
1669
1670         transport_container_unregister(&priv->conn_cont);
1671         transport_container_unregister(&priv->session_cont);
1672         transport_container_unregister(&priv->t.host_attrs);
1673
1674         sysfs_remove_group(&priv->cdev.kobj, &iscsi_transport_group);
1675         class_device_unregister(&priv->cdev);
1676         mutex_unlock(&rx_queue_mutex);
1677
1678         return 0;
1679 }
1680 EXPORT_SYMBOL_GPL(iscsi_unregister_transport);
1681
1682 static __init int iscsi_transport_init(void)
1683 {
1684         int err;
1685
1686         printk(KERN_INFO "Loading iSCSI transport class v%s.\n",
1687                 ISCSI_TRANSPORT_VERSION);
1688
1689         atomic_set(&iscsi_session_nr, 0);
1690
1691         err = class_register(&iscsi_transport_class);
1692         if (err)
1693                 return err;
1694
1695         err = transport_class_register(&iscsi_host_class);
1696         if (err)
1697                 goto unregister_transport_class;
1698
1699         err = transport_class_register(&iscsi_connection_class);
1700         if (err)
1701                 goto unregister_host_class;
1702
1703         err = transport_class_register(&iscsi_session_class);
1704         if (err)
1705                 goto unregister_conn_class;
1706
1707         nls = netlink_kernel_create(&init_net, NETLINK_ISCSI, 1, iscsi_if_rx, NULL,
1708                         THIS_MODULE);
1709         if (!nls) {
1710                 err = -ENOBUFS;
1711                 goto unregister_session_class;
1712         }
1713
1714         iscsi_eh_timer_workq = create_singlethread_workqueue("iscsi_eh");
1715         if (!iscsi_eh_timer_workq)
1716                 goto release_nls;
1717
1718         return 0;
1719
1720 release_nls:
1721         netlink_kernel_release(nls);
1722 unregister_session_class:
1723         transport_class_unregister(&iscsi_session_class);
1724 unregister_conn_class:
1725         transport_class_unregister(&iscsi_connection_class);
1726 unregister_host_class:
1727         transport_class_unregister(&iscsi_host_class);
1728 unregister_transport_class:
1729         class_unregister(&iscsi_transport_class);
1730         return err;
1731 }
1732
1733 static void __exit iscsi_transport_exit(void)
1734 {
1735         destroy_workqueue(iscsi_eh_timer_workq);
1736         netlink_kernel_release(nls);
1737         transport_class_unregister(&iscsi_connection_class);
1738         transport_class_unregister(&iscsi_session_class);
1739         transport_class_unregister(&iscsi_host_class);
1740         class_unregister(&iscsi_transport_class);
1741 }
1742
1743 module_init(iscsi_transport_init);
1744 module_exit(iscsi_transport_exit);
1745
1746 MODULE_AUTHOR("Mike Christie <michaelc@cs.wisc.edu>, "
1747               "Dmitry Yusupov <dmitry_yus@yahoo.com>, "
1748               "Alex Aizman <itn780@yahoo.com>");
1749 MODULE_DESCRIPTION("iSCSI Transport Interface");
1750 MODULE_LICENSE("GPL");
1751 MODULE_VERSION(ISCSI_TRANSPORT_VERSION);