SAFE public projects git trees. - safe/jmp/linux-2.6/blob - 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 11
  35 #define ISCSI_HOST_ATTRS 4
  36 #define ISCSI_TRANSPORT_VERSION "2.0-867"
  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         dev_printk(KERN_INFO, &session->dev, "iscsi: session recovery timed "
 354                   "out after %d secs\n", session->recovery_tmo);
 355
 356         spin_lock_irqsave(&session->lock, flags);
 357         switch (session->state) {
 358         case ISCSI_SESSION_FAILED:
 359                 session->state = ISCSI_SESSION_FREE;
 360                 break;
 361         case ISCSI_SESSION_LOGGED_IN:
 362         case ISCSI_SESSION_FREE:
 363                 /* we raced with the unblock's flush */
 364                 spin_unlock_irqrestore(&session->lock, flags);
 365                 return;
 366         }
 367         spin_unlock_irqrestore(&session->lock, flags);
 368
 369         if (session->transport->session_recovery_timedout)
 370                 session->transport->session_recovery_timedout(session);
 371
 372         scsi_target_unblock(&session->dev);
 373 }
 374
 375 void __iscsi_unblock_session(struct iscsi_cls_session *session)
 376 {
 377         if (!cancel_delayed_work(&session->recovery_work))
 378                 flush_workqueue(iscsi_eh_timer_workq);
 379         scsi_target_unblock(&session->dev);
 380 }
 381
 382 void iscsi_unblock_session(struct iscsi_cls_session *session)
 383 {
 384         struct Scsi_Host *shost = iscsi_session_to_shost(session);
 385         struct iscsi_host *ihost = shost->shost_data;
 386         unsigned long flags;
 387
 388         spin_lock_irqsave(&session->lock, flags);
 389         session->state = ISCSI_SESSION_LOGGED_IN;
 390         spin_unlock_irqrestore(&session->lock, flags);
 391
 392         __iscsi_unblock_session(session);
 393         /*
 394          * Only do kernel scanning if the driver is properly hooked into
 395          * the async scanning code (drivers like iscsi_tcp do login and
 396          * scanning from userspace).
 397          */
 398         if (shost->hostt->scan_finished) {
 399                 if (queue_work(ihost->scan_workq, &session->scan_work))
 400                         atomic_inc(&ihost->nr_scans);
 401         }
 402 }
 403 EXPORT_SYMBOL_GPL(iscsi_unblock_session);
 404
 405 void iscsi_block_session(struct iscsi_cls_session *session)
 406 {
 407         unsigned long flags;
 408
 409         spin_lock_irqsave(&session->lock, flags);
 410         session->state = ISCSI_SESSION_FAILED;
 411         spin_unlock_irqrestore(&session->lock, flags);
 412
 413         scsi_target_block(&session->dev);
 414         queue_delayed_work(iscsi_eh_timer_workq, &session->recovery_work,
 415                            session->recovery_tmo * HZ);
 416 }
 417 EXPORT_SYMBOL_GPL(iscsi_block_session);
 418
 419 static void __iscsi_unbind_session(struct work_struct *work)
 420 {
 421         struct iscsi_cls_session *session =
 422                         container_of(work, struct iscsi_cls_session,
 423                                      unbind_work);
 424         struct Scsi_Host *shost = iscsi_session_to_shost(session);
 425         struct iscsi_host *ihost = shost->shost_data;
 426
 427         /* Prevent new scans and make sure scanning is not in progress */
 428         mutex_lock(&ihost->mutex);
 429         if (list_empty(&session->host_list)) {
 430                 mutex_unlock(&ihost->mutex);
 431                 return;
 432         }
 433         list_del_init(&session->host_list);
 434         mutex_unlock(&ihost->mutex);
 435
 436         scsi_remove_target(&session->dev);
 437         iscsi_session_event(session, ISCSI_KEVENT_UNBIND_SESSION);
 438 }
 439
 440 static int iscsi_unbind_session(struct iscsi_cls_session *session)
 441 {
 442         struct Scsi_Host *shost = iscsi_session_to_shost(session);
 443         struct iscsi_host *ihost = shost->shost_data;
 444
 445         return queue_work(ihost->scan_workq, &session->unbind_work);
 446 }
 447
 448 struct iscsi_cls_session *
 449 iscsi_alloc_session(struct Scsi_Host *shost,
 450                     struct iscsi_transport *transport)
 451 {
 452         struct iscsi_cls_session *session;
 453
 454         session = kzalloc(sizeof(*session) + transport->sessiondata_size,
 455                           GFP_KERNEL);
 456         if (!session)
 457                 return NULL;
 458
 459         session->transport = transport;
 460         session->recovery_tmo = 120;
 461         session->state = ISCSI_SESSION_FREE;
 462         INIT_DELAYED_WORK(&session->recovery_work, session_recovery_timedout);
 463         INIT_LIST_HEAD(&session->host_list);
 464         INIT_LIST_HEAD(&session->sess_list);
 465         INIT_WORK(&session->unbind_work, __iscsi_unbind_session);
 466         INIT_WORK(&session->scan_work, iscsi_scan_session);
 467         spin_lock_init(&session->lock);
 468
 469         /* this is released in the dev's release function */
 470         scsi_host_get(shost);
 471         session->dev.parent = &shost->shost_gendev;
 472         session->dev.release = iscsi_session_release;
 473         device_initialize(&session->dev);
 474         if (transport->sessiondata_size)
 475                 session->dd_data = &session[1];
 476         return session;
 477 }
 478 EXPORT_SYMBOL_GPL(iscsi_alloc_session);
 479
 480 int iscsi_add_session(struct iscsi_cls_session *session, unsigned int target_id)
 481 {
 482         struct Scsi_Host *shost = iscsi_session_to_shost(session);
 483         struct iscsi_host *ihost;
 484         unsigned long flags;
 485         int err;
 486
 487         ihost = shost->shost_data;
 488         session->sid = atomic_add_return(1, &iscsi_session_nr);
 489         session->target_id = target_id;
 490
 491         snprintf(session->dev.bus_id, BUS_ID_SIZE, "session%u",
 492                  session->sid);
 493         err = device_add(&session->dev);
 494         if (err) {
 495                 dev_printk(KERN_ERR, &session->dev, "iscsi: could not "
 496                            "register session's dev\n");
 497                 goto release_host;
 498         }
 499         transport_register_device(&session->dev);
 500
 501         spin_lock_irqsave(&sesslock, flags);
 502         list_add(&session->sess_list, &sesslist);
 503         spin_unlock_irqrestore(&sesslock, flags);
 504
 505         mutex_lock(&ihost->mutex);
 506         list_add(&session->host_list, &ihost->sessions);
 507         mutex_unlock(&ihost->mutex);
 508
 509         iscsi_session_event(session, ISCSI_KEVENT_CREATE_SESSION);
 510         return 0;
 511
 512 release_host:
 513         scsi_host_put(shost);
 514         return err;
 515 }
 516 EXPORT_SYMBOL_GPL(iscsi_add_session);
 517
 518 /**
 519  * iscsi_create_session - create iscsi class session
 520  * @shost: scsi host
 521  * @transport: iscsi transport
 522  * @target_id: which target
 523  *
 524  * This can be called from a LLD or iscsi_transport.
 525  */
 526 struct iscsi_cls_session *
 527 iscsi_create_session(struct Scsi_Host *shost,
 528                      struct iscsi_transport *transport,
 529                      unsigned int target_id)
 530 {
 531         struct iscsi_cls_session *session;
 532
 533         session = iscsi_alloc_session(shost, transport);
 534         if (!session)
 535                 return NULL;
 536
 537         if (iscsi_add_session(session, target_id)) {
 538                 iscsi_free_session(session);
 539                 return NULL;
 540         }
 541         return session;
 542 }
 543 EXPORT_SYMBOL_GPL(iscsi_create_session);
 544
 545 static void iscsi_conn_release(struct device *dev)
 546 {
 547         struct iscsi_cls_conn *conn = iscsi_dev_to_conn(dev);
 548         struct device *parent = conn->dev.parent;
 549
 550         kfree(conn);
 551         put_device(parent);
 552 }
 553
 554 static int iscsi_is_conn_dev(const struct device *dev)
 555 {
 556         return dev->release == iscsi_conn_release;
 557 }
 558
 559 static int iscsi_iter_destroy_conn_fn(struct device *dev, void *data)
 560 {
 561         if (!iscsi_is_conn_dev(dev))
 562                 return 0;
 563         return iscsi_destroy_conn(iscsi_dev_to_conn(dev));
 564 }
 565
 566 void iscsi_remove_session(struct iscsi_cls_session *session)
 567 {
 568         struct Scsi_Host *shost = iscsi_session_to_shost(session);
 569         struct iscsi_host *ihost = shost->shost_data;
 570         unsigned long flags;
 571         int err;
 572
 573         spin_lock_irqsave(&sesslock, flags);
 574         list_del(&session->sess_list);
 575         spin_unlock_irqrestore(&sesslock, flags);
 576
 577         /*
 578          * If we are blocked let commands flow again. The lld or iscsi
 579          * layer should set up the queuecommand to fail commands.
 580          */
 581         spin_lock_irqsave(&session->lock, flags);
 582         session->state = ISCSI_SESSION_FREE;
 583         spin_unlock_irqrestore(&session->lock, flags);
 584         __iscsi_unblock_session(session);
 585         __iscsi_unbind_session(&session->unbind_work);
 586
 587         /* flush running scans */
 588         flush_workqueue(ihost->scan_workq);
 589         /*
 590          * If the session dropped while removing devices then we need to make
 591          * sure it is not blocked
 592          */
 593         if (!cancel_delayed_work(&session->recovery_work))
 594                 flush_workqueue(iscsi_eh_timer_workq);
 595
 596         /* hw iscsi may not have removed all connections from session */
 597         err = device_for_each_child(&session->dev, NULL,
 598                                     iscsi_iter_destroy_conn_fn);
 599         if (err)
 600                 dev_printk(KERN_ERR, &session->dev, "iscsi: Could not delete "
 601                            "all connections for session. Error %d.\n", err);
 602
 603         transport_unregister_device(&session->dev);
 604         device_del(&session->dev);
 605 }
 606 EXPORT_SYMBOL_GPL(iscsi_remove_session);
 607
 608 void iscsi_free_session(struct iscsi_cls_session *session)
 609 {
 610         iscsi_session_event(session, ISCSI_KEVENT_DESTROY_SESSION);
 611         put_device(&session->dev);
 612 }
 613 EXPORT_SYMBOL_GPL(iscsi_free_session);
 614
 615 /**
 616  * iscsi_destroy_session - destroy iscsi session
 617  * @session: iscsi_session
 618  *
 619  * Can be called by a LLD or iscsi_transport. There must not be
 620  * any running connections.
 621  */
 622 int iscsi_destroy_session(struct iscsi_cls_session *session)
 623 {
 624         iscsi_remove_session(session);
 625         iscsi_free_session(session);
 626         return 0;
 627 }
 628 EXPORT_SYMBOL_GPL(iscsi_destroy_session);
 629
 630 /**
 631  * iscsi_create_conn - create iscsi class connection
 632  * @session: iscsi cls session
 633  * @cid: connection id
 634  *
 635  * This can be called from a LLD or iscsi_transport. The connection
 636  * is child of the session so cid must be unique for all connections
 637  * on the session.
 638  *
 639  * Since we do not support MCS, cid will normally be zero. In some cases
 640  * for software iscsi we could be trying to preallocate a connection struct
 641  * in which case there could be two connection structs and cid would be
 642  * non-zero.
 643  */
 644 struct iscsi_cls_conn *
 645 iscsi_create_conn(struct iscsi_cls_session *session, uint32_t cid)
 646 {
 647         struct iscsi_transport *transport = session->transport;
 648         struct iscsi_cls_conn *conn;
 649         unsigned long flags;
 650         int err;
 651
 652         conn = kzalloc(sizeof(*conn) + transport->conndata_size, GFP_KERNEL);
 653         if (!conn)
 654                 return NULL;
 655
 656         if (transport->conndata_size)
 657                 conn->dd_data = &conn[1];
 658
 659         INIT_LIST_HEAD(&conn->conn_list);
 660         conn->transport = transport;
 661         conn->cid = cid;
 662
 663         /* this is released in the dev's release function */
 664         if (!get_device(&session->dev))
 665                 goto free_conn;
 666
 667         snprintf(conn->dev.bus_id, BUS_ID_SIZE, "connection%d:%u",
 668                  session->sid, cid);
 669         conn->dev.parent = &session->dev;
 670         conn->dev.release = iscsi_conn_release;
 671         err = device_register(&conn->dev);
 672         if (err) {
 673                 dev_printk(KERN_ERR, &conn->dev, "iscsi: could not register "
 674                            "connection's dev\n");
 675                 goto release_parent_ref;
 676         }
 677         transport_register_device(&conn->dev);
 678
 679         spin_lock_irqsave(&connlock, flags);
 680         list_add(&conn->conn_list, &connlist);
 681         conn->active = 1;
 682         spin_unlock_irqrestore(&connlock, flags);
 683         return conn;
 684
 685 release_parent_ref:
 686         put_device(&session->dev);
 687 free_conn:
 688         kfree(conn);
 689         return NULL;
 690 }
 691
 692 EXPORT_SYMBOL_GPL(iscsi_create_conn);
 693
 694 /**
 695  * iscsi_destroy_conn - destroy iscsi class connection
 696  * @conn: iscsi cls session
 697  *
 698  * This can be called from a LLD or iscsi_transport.
 699  */
 700 int iscsi_destroy_conn(struct iscsi_cls_conn *conn)
 701 {
 702         unsigned long flags;
 703
 704         spin_lock_irqsave(&connlock, flags);
 705         conn->active = 0;
 706         list_del(&conn->conn_list);
 707         spin_unlock_irqrestore(&connlock, flags);
 708
 709         transport_unregister_device(&conn->dev);
 710         device_unregister(&conn->dev);
 711         return 0;
 712 }
 713 EXPORT_SYMBOL_GPL(iscsi_destroy_conn);
 714
 715 /*
 716  * iscsi interface functions
 717  */
 718 static struct iscsi_internal *
 719 iscsi_if_transport_lookup(struct iscsi_transport *tt)
 720 {
 721         struct iscsi_internal *priv;
 722         unsigned long flags;
 723
 724         spin_lock_irqsave(&iscsi_transport_lock, flags);
 725         list_for_each_entry(priv, &iscsi_transports, list) {
 726                 if (tt == priv->iscsi_transport) {
 727                         spin_unlock_irqrestore(&iscsi_transport_lock, flags);
 728                         return priv;
 729                 }
 730         }
 731         spin_unlock_irqrestore(&iscsi_transport_lock, flags);
 732         return NULL;
 733 }
 734
 735 static int
 736 iscsi_broadcast_skb(struct sk_buff *skb, gfp_t gfp)
 737 {
 738         int rc;
 739
 740         rc = netlink_broadcast(nls, skb, 0, 1, gfp);
 741         if (rc < 0) {
 742                 printk(KERN_ERR "iscsi: can not broadcast skb (%d)\n", rc);
 743                 return rc;
 744         }
 745
 746         return 0;
 747 }
 748
 749 static int
 750 iscsi_unicast_skb(struct sk_buff *skb, int pid)
 751 {
 752         int rc;
 753
 754         rc = netlink_unicast(nls, skb, pid, MSG_DONTWAIT);
 755         if (rc < 0) {
 756                 printk(KERN_ERR "iscsi: can not unicast skb (%d)\n", rc);
 757                 return rc;
 758         }
 759
 760         return 0;
 761 }
 762
 763 int iscsi_recv_pdu(struct iscsi_cls_conn *conn, struct iscsi_hdr *hdr,
 764                    char *data, uint32_t data_size)
 765 {
 766         struct nlmsghdr *nlh;
 767         struct sk_buff *skb;
 768         struct iscsi_uevent *ev;
 769         char *pdu;
 770         struct iscsi_internal *priv;
 771         int len = NLMSG_SPACE(sizeof(*ev) + sizeof(struct iscsi_hdr) +
 772                               data_size);
 773
 774         priv = iscsi_if_transport_lookup(conn->transport);
 775         if (!priv)
 776                 return -EINVAL;
 777
 778         skb = alloc_skb(len, GFP_ATOMIC);
 779         if (!skb) {
 780                 iscsi_conn_error(conn, ISCSI_ERR_CONN_FAILED);
 781                 dev_printk(KERN_ERR, &conn->dev, "iscsi: can not deliver "
 782                            "control PDU: OOM\n");
 783                 return -ENOMEM;
 784         }
 785
 786         nlh = __nlmsg_put(skb, priv->daemon_pid, 0, 0, (len - sizeof(*nlh)), 0);
 787         ev = NLMSG_DATA(nlh);
 788         memset(ev, 0, sizeof(*ev));
 789         ev->transport_handle = iscsi_handle(conn->transport);
 790         ev->type = ISCSI_KEVENT_RECV_PDU;
 791         ev->r.recv_req.cid = conn->cid;
 792         ev->r.recv_req.sid = iscsi_conn_get_sid(conn);
 793         pdu = (char*)ev + sizeof(*ev);
 794         memcpy(pdu, hdr, sizeof(struct iscsi_hdr));
 795         memcpy(pdu + sizeof(struct iscsi_hdr), data, data_size);
 796
 797         return iscsi_unicast_skb(skb, priv->daemon_pid);
 798 }
 799 EXPORT_SYMBOL_GPL(iscsi_recv_pdu);
 800
 801 void iscsi_conn_error(struct iscsi_cls_conn *conn, enum iscsi_err error)
 802 {
 803         struct iscsi_cls_session *session = iscsi_conn_to_session(conn);
 804         struct nlmsghdr *nlh;
 805         struct sk_buff  *skb;
 806         struct iscsi_uevent *ev;
 807         struct iscsi_internal *priv;
 808         int len = NLMSG_SPACE(sizeof(*ev));
 809         unsigned long flags;
 810
 811         priv = iscsi_if_transport_lookup(conn->transport);
 812         if (!priv)
 813                 return;
 814
 815         spin_lock_irqsave(&session->lock, flags);
 816         if (session->state == ISCSI_SESSION_LOGGED_IN)
 817                 session->state = ISCSI_SESSION_FAILED;
 818         spin_unlock_irqrestore(&session->lock, flags);
 819
 820         skb = alloc_skb(len, GFP_ATOMIC);
 821         if (!skb) {
 822                 dev_printk(KERN_ERR, &conn->dev, "iscsi: gracefully ignored "
 823                           "conn error (%d)\n", error);
 824                 return;
 825         }
 826
 827         nlh = __nlmsg_put(skb, priv->daemon_pid, 0, 0, (len - sizeof(*nlh)), 0);
 828         ev = NLMSG_DATA(nlh);
 829         ev->transport_handle = iscsi_handle(conn->transport);
 830         ev->type = ISCSI_KEVENT_CONN_ERROR;
 831         ev->r.connerror.error = error;
 832         ev->r.connerror.cid = conn->cid;
 833         ev->r.connerror.sid = iscsi_conn_get_sid(conn);
 834
 835         iscsi_broadcast_skb(skb, GFP_ATOMIC);
 836
 837         dev_printk(KERN_INFO, &conn->dev, "iscsi: detected conn error (%d)\n",
 838                    error);
 839 }
 840 EXPORT_SYMBOL_GPL(iscsi_conn_error);
 841
 842 static int
 843 iscsi_if_send_reply(int pid, int seq, int type, int done, int multi,
 844                       void *payload, int size)
 845 {
 846         struct sk_buff  *skb;
 847         struct nlmsghdr *nlh;
 848         int len = NLMSG_SPACE(size);
 849         int flags = multi ? NLM_F_MULTI : 0;
 850         int t = done ? NLMSG_DONE : type;
 851
 852         skb = alloc_skb(len, GFP_ATOMIC);
 853         if (!skb) {
 854                 printk(KERN_ERR "Could not allocate skb to send reply.\n");
 855                 return -ENOMEM;
 856         }
 857
 858         nlh = __nlmsg_put(skb, pid, seq, t, (len - sizeof(*nlh)), 0);
 859         nlh->nlmsg_flags = flags;
 860         memcpy(NLMSG_DATA(nlh), payload, size);
 861         return iscsi_unicast_skb(skb, pid);
 862 }
 863
 864 static int
 865 iscsi_if_get_stats(struct iscsi_transport *transport, struct nlmsghdr *nlh)
 866 {
 867         struct iscsi_uevent *ev = NLMSG_DATA(nlh);
 868         struct iscsi_stats *stats;
 869         struct sk_buff *skbstat;
 870         struct iscsi_cls_conn *conn;
 871         struct nlmsghdr *nlhstat;
 872         struct iscsi_uevent *evstat;
 873         struct iscsi_internal *priv;
 874         int len = NLMSG_SPACE(sizeof(*ev) +
 875                               sizeof(struct iscsi_stats) +
 876                               sizeof(struct iscsi_stats_custom) *
 877                               ISCSI_STATS_CUSTOM_MAX);
 878         int err = 0;
 879
 880         priv = iscsi_if_transport_lookup(transport);
 881         if (!priv)
 882                 return -EINVAL;
 883
 884         conn = iscsi_conn_lookup(ev->u.get_stats.sid, ev->u.get_stats.cid);
 885         if (!conn)
 886                 return -EEXIST;
 887
 888         do {
 889                 int actual_size;
 890
 891                 skbstat = alloc_skb(len, GFP_ATOMIC);
 892                 if (!skbstat) {
 893                         dev_printk(KERN_ERR, &conn->dev, "iscsi: can not "
 894                                    "deliver stats: OOM\n");
 895                         return -ENOMEM;
 896                 }
 897
 898                 nlhstat = __nlmsg_put(skbstat, priv->daemon_pid, 0, 0,
 899                                       (len - sizeof(*nlhstat)), 0);
 900                 evstat = NLMSG_DATA(nlhstat);
 901                 memset(evstat, 0, sizeof(*evstat));
 902                 evstat->transport_handle = iscsi_handle(conn->transport);
 903                 evstat->type = nlh->nlmsg_type;
 904                 evstat->u.get_stats.cid =
 905                         ev->u.get_stats.cid;
 906                 evstat->u.get_stats.sid =
 907                         ev->u.get_stats.sid;
 908                 stats = (struct iscsi_stats *)
 909                         ((char*)evstat + sizeof(*evstat));
 910                 memset(stats, 0, sizeof(*stats));
 911
 912                 transport->get_stats(conn, stats);
 913                 actual_size = NLMSG_SPACE(sizeof(struct iscsi_uevent) +
 914                                           sizeof(struct iscsi_stats) +
 915                                           sizeof(struct iscsi_stats_custom) *
 916                                           stats->custom_length);
 917                 actual_size -= sizeof(*nlhstat);
 918                 actual_size = NLMSG_LENGTH(actual_size);
 919                 skb_trim(skbstat, NLMSG_ALIGN(actual_size));
 920                 nlhstat->nlmsg_len = actual_size;
 921
 922                 err = iscsi_unicast_skb(skbstat, priv->daemon_pid);
 923         } while (err < 0 && err != -ECONNREFUSED);
 924
 925         return err;
 926 }
 927
 928 /**
 929  * iscsi_session_event - send session destr. completion event
 930  * @session: iscsi class session
 931  * @event: type of event
 932  */
 933 int iscsi_session_event(struct iscsi_cls_session *session,
 934                         enum iscsi_uevent_e event)
 935 {
 936         struct iscsi_internal *priv;
 937         struct Scsi_Host *shost;
 938         struct iscsi_uevent *ev;
 939         struct sk_buff  *skb;
 940         struct nlmsghdr *nlh;
 941         int rc, len = NLMSG_SPACE(sizeof(*ev));
 942
 943         priv = iscsi_if_transport_lookup(session->transport);
 944         if (!priv)
 945                 return -EINVAL;
 946         shost = iscsi_session_to_shost(session);
 947
 948         skb = alloc_skb(len, GFP_KERNEL);
 949         if (!skb) {
 950                 dev_printk(KERN_ERR, &session->dev, "Cannot notify userspace "
 951                           "of session event %u\n", event);
 952                 return -ENOMEM;
 953         }
 954
 955         nlh = __nlmsg_put(skb, priv->daemon_pid, 0, 0, (len - sizeof(*nlh)), 0);
 956         ev = NLMSG_DATA(nlh);
 957         ev->transport_handle = iscsi_handle(session->transport);
 958
 959         ev->type = event;
 960         switch (event) {
 961         case ISCSI_KEVENT_DESTROY_SESSION:
 962                 ev->r.d_session.host_no = shost->host_no;
 963                 ev->r.d_session.sid = session->sid;
 964                 break;
 965         case ISCSI_KEVENT_CREATE_SESSION:
 966                 ev->r.c_session_ret.host_no = shost->host_no;
 967                 ev->r.c_session_ret.sid = session->sid;
 968                 break;
 969         case ISCSI_KEVENT_UNBIND_SESSION:
 970                 ev->r.unbind_session.host_no = shost->host_no;
 971                 ev->r.unbind_session.sid = session->sid;
 972                 break;
 973         default:
 974                 dev_printk(KERN_ERR, &session->dev, "Invalid event %u.\n",
 975                            event);
 976                 kfree_skb(skb);
 977                 return -EINVAL;
 978         }
 979
 980         /*
 981          * this will occur if the daemon is not up, so we just warn
 982          * the user and when the daemon is restarted it will handle it
 983          */
 984         rc = iscsi_broadcast_skb(skb, GFP_KERNEL);
 985         if (rc < 0)
 986                 dev_printk(KERN_ERR, &session->dev, "Cannot notify userspace "
 987                           "of session event %u. Check iscsi daemon\n", event);
 988         return rc;
 989 }
 990 EXPORT_SYMBOL_GPL(iscsi_session_event);
 991
 992 static int
 993 iscsi_if_create_session(struct iscsi_internal *priv, struct iscsi_uevent *ev)
 994 {
 995         struct iscsi_transport *transport = priv->iscsi_transport;
 996         struct iscsi_cls_session *session;
 997         uint32_t hostno;
 998
 999         session = transport->create_session(transport, &priv->t,
1000                                             ev->u.c_session.cmds_max,
1001                                             ev->u.c_session.queue_depth,
1002                                             ev->u.c_session.initial_cmdsn,
1003                                             &hostno);
1004         if (!session)
1005                 return -ENOMEM;
1006
1007         ev->r.c_session_ret.host_no = hostno;
1008         ev->r.c_session_ret.sid = session->sid;
1009         return 0;
1010 }
1011
1012 static int
1013 iscsi_if_create_conn(struct iscsi_transport *transport, struct iscsi_uevent *ev)
1014 {
1015         struct iscsi_cls_conn *conn;
1016         struct iscsi_cls_session *session;
1017
1018         session = iscsi_session_lookup(ev->u.c_conn.sid);
1019         if (!session) {
1020                 printk(KERN_ERR "iscsi: invalid session %d\n",
1021                        ev->u.c_conn.sid);
1022                 return -EINVAL;
1023         }
1024
1025         conn = transport->create_conn(session, ev->u.c_conn.cid);
1026         if (!conn) {
1027                 printk(KERN_ERR "iscsi: couldn't create a new "
1028                            "connection for session %d\n",
1029                            session->sid);
1030                 return -ENOMEM;
1031         }
1032
1033         ev->r.c_conn_ret.sid = session->sid;
1034         ev->r.c_conn_ret.cid = conn->cid;
1035         return 0;
1036 }
1037
1038 static int
1039 iscsi_if_destroy_conn(struct iscsi_transport *transport, struct iscsi_uevent *ev)
1040 {
1041         struct iscsi_cls_conn *conn;
1042
1043         conn = iscsi_conn_lookup(ev->u.d_conn.sid, ev->u.d_conn.cid);
1044         if (!conn)
1045                 return -EINVAL;
1046
1047         if (transport->destroy_conn)
1048                 transport->destroy_conn(conn);
1049         return 0;
1050 }
1051
1052 static int
1053 iscsi_set_param(struct iscsi_transport *transport, struct iscsi_uevent *ev)
1054 {
1055         char *data = (char*)ev + sizeof(*ev);
1056         struct iscsi_cls_conn *conn;
1057         struct iscsi_cls_session *session;
1058         int err = 0, value = 0;
1059
1060         session = iscsi_session_lookup(ev->u.set_param.sid);
1061         conn = iscsi_conn_lookup(ev->u.set_param.sid, ev->u.set_param.cid);
1062         if (!conn || !session)
1063                 return -EINVAL;
1064
1065         switch (ev->u.set_param.param) {
1066         case ISCSI_PARAM_SESS_RECOVERY_TMO:
1067                 sscanf(data, "%d", &value);
1068                 if (value != 0)
1069                         session->recovery_tmo = value;
1070                 break;
1071         default:
1072                 err = transport->set_param(conn, ev->u.set_param.param,
1073                                            data, ev->u.set_param.len);
1074         }
1075
1076         return err;
1077 }
1078
1079 static int
1080 iscsi_if_transport_ep(struct iscsi_transport *transport,
1081                       struct iscsi_uevent *ev, int msg_type)
1082 {
1083         struct sockaddr *dst_addr;
1084         int rc = 0;
1085
1086         switch (msg_type) {
1087         case ISCSI_UEVENT_TRANSPORT_EP_CONNECT:
1088                 if (!transport->ep_connect)
1089                         return -EINVAL;
1090
1091                 dst_addr = (struct sockaddr *)((char*)ev + sizeof(*ev));
1092                 rc = transport->ep_connect(dst_addr,
1093                                            ev->u.ep_connect.non_blocking,
1094                                            &ev->r.ep_connect_ret.handle);
1095                 break;
1096         case ISCSI_UEVENT_TRANSPORT_EP_POLL:
1097                 if (!transport->ep_poll)
1098                         return -EINVAL;
1099
1100                 ev->r.retcode = transport->ep_poll(ev->u.ep_poll.ep_handle,
1101                                                    ev->u.ep_poll.timeout_ms);
1102                 break;
1103         case ISCSI_UEVENT_TRANSPORT_EP_DISCONNECT:
1104                 if (!transport->ep_disconnect)
1105                         return -EINVAL;
1106
1107                 transport->ep_disconnect(ev->u.ep_disconnect.ep_handle);
1108                 break;
1109         }
1110         return rc;
1111 }
1112
1113 static int
1114 iscsi_tgt_dscvr(struct iscsi_transport *transport,
1115                 struct iscsi_uevent *ev)
1116 {
1117         struct Scsi_Host *shost;
1118         struct sockaddr *dst_addr;
1119         int err;
1120
1121         if (!transport->tgt_dscvr)
1122                 return -EINVAL;
1123
1124         shost = scsi_host_lookup(ev->u.tgt_dscvr.host_no);
1125         if (IS_ERR(shost)) {
1126                 printk(KERN_ERR "target discovery could not find host no %u\n",
1127                        ev->u.tgt_dscvr.host_no);
1128                 return -ENODEV;
1129         }
1130
1131
1132         dst_addr = (struct sockaddr *)((char*)ev + sizeof(*ev));
1133         err = transport->tgt_dscvr(shost, ev->u.tgt_dscvr.type,
1134                                    ev->u.tgt_dscvr.enable, dst_addr);
1135         scsi_host_put(shost);
1136         return err;
1137 }
1138
1139 static int
1140 iscsi_set_host_param(struct iscsi_transport *transport,
1141                      struct iscsi_uevent *ev)
1142 {
1143         char *data = (char*)ev + sizeof(*ev);
1144         struct Scsi_Host *shost;
1145         int err;
1146
1147         if (!transport->set_host_param)
1148                 return -ENOSYS;
1149
1150         shost = scsi_host_lookup(ev->u.set_host_param.host_no);
1151         if (IS_ERR(shost)) {
1152                 printk(KERN_ERR "set_host_param could not find host no %u\n",
1153                        ev->u.set_host_param.host_no);
1154                 return -ENODEV;
1155         }
1156
1157         err = transport->set_host_param(shost, ev->u.set_host_param.param,
1158                                         data, ev->u.set_host_param.len);
1159         scsi_host_put(shost);
1160         return err;
1161 }
1162
1163 static int
1164 iscsi_if_recv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
1165 {
1166         int err = 0;
1167         struct iscsi_uevent *ev = NLMSG_DATA(nlh);
1168         struct iscsi_transport *transport = NULL;
1169         struct iscsi_internal *priv;
1170         struct iscsi_cls_session *session;
1171         struct iscsi_cls_conn *conn;
1172
1173         priv = iscsi_if_transport_lookup(iscsi_ptr(ev->transport_handle));
1174         if (!priv)
1175                 return -EINVAL;
1176         transport = priv->iscsi_transport;
1177
1178         if (!try_module_get(transport->owner))
1179                 return -EINVAL;
1180
1181         priv->daemon_pid = NETLINK_CREDS(skb)->pid;
1182
1183         switch (nlh->nlmsg_type) {
1184         case ISCSI_UEVENT_CREATE_SESSION:
1185                 err = iscsi_if_create_session(priv, ev);
1186                 break;
1187         case ISCSI_UEVENT_DESTROY_SESSION:
1188                 session = iscsi_session_lookup(ev->u.d_session.sid);
1189                 if (session)
1190                         transport->destroy_session(session);
1191                 else
1192                         err = -EINVAL;
1193                 break;
1194         case ISCSI_UEVENT_UNBIND_SESSION:
1195                 session = iscsi_session_lookup(ev->u.d_session.sid);
1196                 if (session)
1197                         iscsi_unbind_session(session);
1198                 else
1199                         err = -EINVAL;
1200                 break;
1201         case ISCSI_UEVENT_CREATE_CONN:
1202                 err = iscsi_if_create_conn(transport, ev);
1203                 break;
1204         case ISCSI_UEVENT_DESTROY_CONN:
1205                 err = iscsi_if_destroy_conn(transport, ev);
1206                 break;
1207         case ISCSI_UEVENT_BIND_CONN:
1208                 session = iscsi_session_lookup(ev->u.b_conn.sid);
1209                 conn = iscsi_conn_lookup(ev->u.b_conn.sid, ev->u.b_conn.cid);
1210
1211                 if (session && conn)
1212                         ev->r.retcode = transport->bind_conn(session, conn,
1213                                         ev->u.b_conn.transport_eph,
1214                                         ev->u.b_conn.is_leading);
1215                 else
1216                         err = -EINVAL;
1217                 break;
1218         case ISCSI_UEVENT_SET_PARAM:
1219                 err = iscsi_set_param(transport, ev);
1220                 break;
1221         case ISCSI_UEVENT_START_CONN:
1222                 conn = iscsi_conn_lookup(ev->u.start_conn.sid, ev->u.start_conn.cid);
1223                 if (conn)
1224                         ev->r.retcode = transport->start_conn(conn);
1225                 else
1226                         err = -EINVAL;
1227                 break;
1228         case ISCSI_UEVENT_STOP_CONN:
1229                 conn = iscsi_conn_lookup(ev->u.stop_conn.sid, ev->u.stop_conn.cid);
1230                 if (conn)
1231                         transport->stop_conn(conn, ev->u.stop_conn.flag);
1232                 else
1233                         err = -EINVAL;
1234                 break;
1235         case ISCSI_UEVENT_SEND_PDU:
1236                 conn = iscsi_conn_lookup(ev->u.send_pdu.sid, ev->u.send_pdu.cid);
1237                 if (conn)
1238                         ev->r.retcode = transport->send_pdu(conn,
1239                                 (struct iscsi_hdr*)((char*)ev + sizeof(*ev)),
1240                                 (char*)ev + sizeof(*ev) + ev->u.send_pdu.hdr_size,
1241                                 ev->u.send_pdu.data_size);
1242                 else
1243                         err = -EINVAL;
1244                 break;
1245         case ISCSI_UEVENT_GET_STATS:
1246                 err = iscsi_if_get_stats(transport, nlh);
1247                 break;
1248         case ISCSI_UEVENT_TRANSPORT_EP_CONNECT:
1249         case ISCSI_UEVENT_TRANSPORT_EP_POLL:
1250         case ISCSI_UEVENT_TRANSPORT_EP_DISCONNECT:
1251                 err = iscsi_if_transport_ep(transport, ev, nlh->nlmsg_type);
1252                 break;
1253         case ISCSI_UEVENT_TGT_DSCVR:
1254                 err = iscsi_tgt_dscvr(transport, ev);
1255                 break;
1256         case ISCSI_UEVENT_SET_HOST_PARAM:
1257                 err = iscsi_set_host_param(transport, ev);
1258                 break;
1259         default:
1260                 err = -ENOSYS;
1261                 break;
1262         }
1263
1264         module_put(transport->owner);
1265         return err;
1266 }
1267
1268 /*
1269  * Get message from skb.  Each message is processed by iscsi_if_recv_msg.
1270  * Malformed skbs with wrong lengths or invalid creds are not processed.
1271  */
1272 static void
1273 iscsi_if_rx(struct sk_buff *skb)
1274 {
1275         mutex_lock(&rx_queue_mutex);
1276         while (skb->len >= NLMSG_SPACE(0)) {
1277                 int err;
1278                 uint32_t rlen;
1279                 struct nlmsghdr *nlh;
1280                 struct iscsi_uevent *ev;
1281
1282                 nlh = nlmsg_hdr(skb);
1283                 if (nlh->nlmsg_len < sizeof(*nlh) ||
1284                     skb->len < nlh->nlmsg_len) {
1285                         break;
1286                 }
1287
1288                 ev = NLMSG_DATA(nlh);
1289                 rlen = NLMSG_ALIGN(nlh->nlmsg_len);
1290                 if (rlen > skb->len)
1291                         rlen = skb->len;
1292
1293                 err = iscsi_if_recv_msg(skb, nlh);
1294                 if (err) {
1295                         ev->type = ISCSI_KEVENT_IF_ERROR;
1296                         ev->iferror = err;
1297                 }
1298                 do {
1299                         /*
1300                          * special case for GET_STATS:
1301                          * on success - sending reply and stats from
1302                          * inside of if_recv_msg(),
1303                          * on error - fall through.
1304                          */
1305                         if (ev->type == ISCSI_UEVENT_GET_STATS && !err)
1306                                 break;
1307                         err = iscsi_if_send_reply(
1308                                 NETLINK_CREDS(skb)->pid, nlh->nlmsg_seq,
1309                                 nlh->nlmsg_type, 0, 0, ev, sizeof(*ev));
1310                 } while (err < 0 && err != -ECONNREFUSED);
1311                 skb_pull(skb, rlen);
1312         }
1313         mutex_unlock(&rx_queue_mutex);
1314 }
1315
1316 #define iscsi_cdev_to_conn(_cdev) \
1317         iscsi_dev_to_conn(_cdev->dev)
1318
1319 #define ISCSI_CLASS_ATTR(_prefix,_name,_mode,_show,_store)              \
1320 struct class_device_attribute class_device_attr_##_prefix##_##_name =   \
1321         __ATTR(_name,_mode,_show,_store)
1322
1323 /*
1324  * iSCSI connection attrs
1325  */
1326 #define iscsi_conn_attr_show(param)                                     \
1327 static ssize_t                                                          \
1328 show_conn_param_##param(struct class_device *cdev, char *buf)           \
1329 {                                                                       \
1330         struct iscsi_cls_conn *conn = iscsi_cdev_to_conn(cdev);         \
1331         struct iscsi_transport *t = conn->transport;                    \
1332         return t->get_conn_param(conn, param, buf);                     \
1333 }
1334
1335 #define iscsi_conn_attr(field, param)                                   \
1336         iscsi_conn_attr_show(param)                                     \
1337 static ISCSI_CLASS_ATTR(conn, field, S_IRUGO, show_conn_param_##param,  \
1338                         NULL);
1339
1340 iscsi_conn_attr(max_recv_dlength, ISCSI_PARAM_MAX_RECV_DLENGTH);
1341 iscsi_conn_attr(max_xmit_dlength, ISCSI_PARAM_MAX_XMIT_DLENGTH);
1342 iscsi_conn_attr(header_digest, ISCSI_PARAM_HDRDGST_EN);
1343 iscsi_conn_attr(data_digest, ISCSI_PARAM_DATADGST_EN);
1344 iscsi_conn_attr(ifmarker, ISCSI_PARAM_IFMARKER_EN);
1345 iscsi_conn_attr(ofmarker, ISCSI_PARAM_OFMARKER_EN);
1346 iscsi_conn_attr(persistent_port, ISCSI_PARAM_PERSISTENT_PORT);
1347 iscsi_conn_attr(port, ISCSI_PARAM_CONN_PORT);
1348 iscsi_conn_attr(exp_statsn, ISCSI_PARAM_EXP_STATSN);
1349 iscsi_conn_attr(persistent_address, ISCSI_PARAM_PERSISTENT_ADDRESS);
1350 iscsi_conn_attr(address, ISCSI_PARAM_CONN_ADDRESS);
1351 iscsi_conn_attr(ping_tmo, ISCSI_PARAM_PING_TMO);
1352 iscsi_conn_attr(recv_tmo, ISCSI_PARAM_RECV_TMO);
1353
1354 #define iscsi_cdev_to_session(_cdev) \
1355         iscsi_dev_to_session(_cdev->dev)
1356
1357 /*
1358  * iSCSI session attrs
1359  */
1360 #define iscsi_session_attr_show(param, perm)                            \
1361 static ssize_t                                                          \
1362 show_session_param_##param(struct class_device *cdev, char *buf)        \
1363 {                                                                       \
1364         struct iscsi_cls_session *session = iscsi_cdev_to_session(cdev); \
1365         struct iscsi_transport *t = session->transport;                 \
1366                                                                         \
1367         if (perm && !capable(CAP_SYS_ADMIN))                            \
1368                 return -EACCES;                                         \
1369         return t->get_session_param(session, param, buf);               \
1370 }
1371
1372 #define iscsi_session_attr(field, param, perm)                          \
1373         iscsi_session_attr_show(param, perm)                            \
1374 static ISCSI_CLASS_ATTR(sess, field, S_IRUGO, show_session_param_##param, \
1375                         NULL);
1376
1377 iscsi_session_attr(targetname, ISCSI_PARAM_TARGET_NAME, 0);
1378 iscsi_session_attr(initial_r2t, ISCSI_PARAM_INITIAL_R2T_EN, 0);
1379 iscsi_session_attr(max_outstanding_r2t, ISCSI_PARAM_MAX_R2T, 0);
1380 iscsi_session_attr(immediate_data, ISCSI_PARAM_IMM_DATA_EN, 0);
1381 iscsi_session_attr(first_burst_len, ISCSI_PARAM_FIRST_BURST, 0);
1382 iscsi_session_attr(max_burst_len, ISCSI_PARAM_MAX_BURST, 0);
1383 iscsi_session_attr(data_pdu_in_order, ISCSI_PARAM_PDU_INORDER_EN, 0);
1384 iscsi_session_attr(data_seq_in_order, ISCSI_PARAM_DATASEQ_INORDER_EN, 0);
1385 iscsi_session_attr(erl, ISCSI_PARAM_ERL, 0);
1386 iscsi_session_attr(tpgt, ISCSI_PARAM_TPGT, 0);
1387 iscsi_session_attr(username, ISCSI_PARAM_USERNAME, 1);
1388 iscsi_session_attr(username_in, ISCSI_PARAM_USERNAME_IN, 1);
1389 iscsi_session_attr(password, ISCSI_PARAM_PASSWORD, 1);
1390 iscsi_session_attr(password_in, ISCSI_PARAM_PASSWORD_IN, 1);
1391 iscsi_session_attr(fast_abort, ISCSI_PARAM_FAST_ABORT, 0);
1392 iscsi_session_attr(abort_tmo, ISCSI_PARAM_ABORT_TMO, 0);
1393 iscsi_session_attr(lu_reset_tmo, ISCSI_PARAM_LU_RESET_TMO, 0);
1394
1395 static ssize_t
1396 show_priv_session_state(struct class_device *cdev, char *buf)
1397 {
1398         struct iscsi_cls_session *session = iscsi_cdev_to_session(cdev);
1399         return sprintf(buf, "%s\n", iscsi_session_state_name(session->state));
1400 }
1401 static ISCSI_CLASS_ATTR(priv_sess, state, S_IRUGO, show_priv_session_state,
1402                         NULL);
1403
1404 #define iscsi_priv_session_attr_show(field, format)                     \
1405 static ssize_t                                                          \
1406 show_priv_session_##field(struct class_device *cdev, char *buf)         \
1407 {                                                                       \
1408         struct iscsi_cls_session *session = iscsi_cdev_to_session(cdev);\
1409         return sprintf(buf, format"\n", session->field);                \
1410 }
1411
1412 #define iscsi_priv_session_attr(field, format)                          \
1413         iscsi_priv_session_attr_show(field, format)                     \
1414 static ISCSI_CLASS_ATTR(priv_sess, field, S_IRUGO, show_priv_session_##field, \
1415                         NULL)
1416 iscsi_priv_session_attr(recovery_tmo, "%d");
1417
1418 /*
1419  * iSCSI host attrs
1420  */
1421 #define iscsi_host_attr_show(param)                                     \
1422 static ssize_t                                                          \
1423 show_host_param_##param(struct class_device *cdev, char *buf)           \
1424 {                                                                       \
1425         struct Scsi_Host *shost = transport_class_to_shost(cdev);       \
1426         struct iscsi_internal *priv = to_iscsi_internal(shost->transportt); \
1427         return priv->iscsi_transport->get_host_param(shost, param, buf); \
1428 }
1429
1430 #define iscsi_host_attr(field, param)                                   \
1431         iscsi_host_attr_show(param)                                     \
1432 static ISCSI_CLASS_ATTR(host, field, S_IRUGO, show_host_param_##param,  \
1433                         NULL);
1434
1435 iscsi_host_attr(netdev, ISCSI_HOST_PARAM_NETDEV_NAME);
1436 iscsi_host_attr(hwaddress, ISCSI_HOST_PARAM_HWADDRESS);
1437 iscsi_host_attr(ipaddress, ISCSI_HOST_PARAM_IPADDRESS);
1438 iscsi_host_attr(initiatorname, ISCSI_HOST_PARAM_INITIATOR_NAME);
1439
1440 #define SETUP_PRIV_SESSION_RD_ATTR(field)                               \
1441 do {                                                                    \
1442         priv->session_attrs[count] = &class_device_attr_priv_sess_##field; \
1443         count++;                                                        \
1444 } while (0)
1445
1446
1447 #define SETUP_SESSION_RD_ATTR(field, param_flag)                        \
1448 do {                                                                    \
1449         if (tt->param_mask & param_flag) {                              \
1450                 priv->session_attrs[count] = &class_device_attr_sess_##field; \
1451                 count++;                                                \
1452         }                                                               \
1453 } while (0)
1454
1455 #define SETUP_CONN_RD_ATTR(field, param_flag)                           \
1456 do {                                                                    \
1457         if (tt->param_mask & param_flag) {                              \
1458                 priv->conn_attrs[count] = &class_device_attr_conn_##field; \
1459                 count++;                                                \
1460         }                                                               \
1461 } while (0)
1462
1463 #define SETUP_HOST_RD_ATTR(field, param_flag)                           \
1464 do {                                                                    \
1465         if (tt->host_param_mask & param_flag) {                         \
1466                 priv->host_attrs[count] = &class_device_attr_host_##field; \
1467                 count++;                                                \
1468         }                                                               \
1469 } while (0)
1470
1471 static int iscsi_session_match(struct attribute_container *cont,
1472                            struct device *dev)
1473 {
1474         struct iscsi_cls_session *session;
1475         struct Scsi_Host *shost;
1476         struct iscsi_internal *priv;
1477
1478         if (!iscsi_is_session_dev(dev))
1479                 return 0;
1480
1481         session = iscsi_dev_to_session(dev);
1482         shost = iscsi_session_to_shost(session);
1483         if (!shost->transportt)
1484                 return 0;
1485
1486         priv = to_iscsi_internal(shost->transportt);
1487         if (priv->session_cont.ac.class != &iscsi_session_class.class)
1488                 return 0;
1489
1490         return &priv->session_cont.ac == cont;
1491 }
1492
1493 static int iscsi_conn_match(struct attribute_container *cont,
1494                            struct device *dev)
1495 {
1496         struct iscsi_cls_session *session;
1497         struct iscsi_cls_conn *conn;
1498         struct Scsi_Host *shost;
1499         struct iscsi_internal *priv;
1500
1501         if (!iscsi_is_conn_dev(dev))
1502                 return 0;
1503
1504         conn = iscsi_dev_to_conn(dev);
1505         session = iscsi_dev_to_session(conn->dev.parent);
1506         shost = iscsi_session_to_shost(session);
1507
1508         if (!shost->transportt)
1509                 return 0;
1510
1511         priv = to_iscsi_internal(shost->transportt);
1512         if (priv->conn_cont.ac.class != &iscsi_connection_class.class)
1513                 return 0;
1514
1515         return &priv->conn_cont.ac == cont;
1516 }
1517
1518 static int iscsi_host_match(struct attribute_container *cont,
1519                             struct device *dev)
1520 {
1521         struct Scsi_Host *shost;
1522         struct iscsi_internal *priv;
1523
1524         if (!scsi_is_host_device(dev))
1525                 return 0;
1526
1527         shost = dev_to_shost(dev);
1528         if (!shost->transportt  ||
1529             shost->transportt->host_attrs.ac.class != &iscsi_host_class.class)
1530                 return 0;
1531
1532         priv = to_iscsi_internal(shost->transportt);
1533         return &priv->t.host_attrs.ac == cont;
1534 }
1535
1536 struct scsi_transport_template *
1537 iscsi_register_transport(struct iscsi_transport *tt)
1538 {
1539         struct iscsi_internal *priv;
1540         unsigned long flags;
1541         int count = 0, err;
1542
1543         BUG_ON(!tt);
1544
1545         priv = iscsi_if_transport_lookup(tt);
1546         if (priv)
1547                 return NULL;
1548
1549         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
1550         if (!priv)
1551                 return NULL;
1552         INIT_LIST_HEAD(&priv->list);
1553         priv->daemon_pid = -1;
1554         priv->iscsi_transport = tt;
1555         priv->t.user_scan = iscsi_user_scan;
1556
1557         priv->cdev.class = &iscsi_transport_class;
1558         snprintf(priv->cdev.class_id, BUS_ID_SIZE, "%s", tt->name);
1559         err = class_device_register(&priv->cdev);
1560         if (err)
1561                 goto free_priv;
1562
1563         err = sysfs_create_group(&priv->cdev.kobj, &iscsi_transport_group);
1564         if (err)
1565                 goto unregister_cdev;
1566
1567         /* host parameters */
1568         priv->t.host_attrs.ac.attrs = &priv->host_attrs[0];
1569         priv->t.host_attrs.ac.class = &iscsi_host_class.class;
1570         priv->t.host_attrs.ac.match = iscsi_host_match;
1571         priv->t.host_size = sizeof(struct iscsi_host);
1572         transport_container_register(&priv->t.host_attrs);
1573
1574         SETUP_HOST_RD_ATTR(netdev, ISCSI_HOST_NETDEV_NAME);
1575         SETUP_HOST_RD_ATTR(ipaddress, ISCSI_HOST_IPADDRESS);
1576         SETUP_HOST_RD_ATTR(hwaddress, ISCSI_HOST_HWADDRESS);
1577         SETUP_HOST_RD_ATTR(initiatorname, ISCSI_HOST_INITIATOR_NAME);
1578         BUG_ON(count > ISCSI_HOST_ATTRS);
1579         priv->host_attrs[count] = NULL;
1580         count = 0;
1581
1582         /* connection parameters */
1583         priv->conn_cont.ac.attrs = &priv->conn_attrs[0];
1584         priv->conn_cont.ac.class = &iscsi_connection_class.class;
1585         priv->conn_cont.ac.match = iscsi_conn_match;
1586         transport_container_register(&priv->conn_cont);
1587
1588         SETUP_CONN_RD_ATTR(max_recv_dlength, ISCSI_MAX_RECV_DLENGTH);
1589         SETUP_CONN_RD_ATTR(max_xmit_dlength, ISCSI_MAX_XMIT_DLENGTH);
1590         SETUP_CONN_RD_ATTR(header_digest, ISCSI_HDRDGST_EN);
1591         SETUP_CONN_RD_ATTR(data_digest, ISCSI_DATADGST_EN);
1592         SETUP_CONN_RD_ATTR(ifmarker, ISCSI_IFMARKER_EN);
1593         SETUP_CONN_RD_ATTR(ofmarker, ISCSI_OFMARKER_EN);
1594         SETUP_CONN_RD_ATTR(address, ISCSI_CONN_ADDRESS);
1595         SETUP_CONN_RD_ATTR(port, ISCSI_CONN_PORT);
1596         SETUP_CONN_RD_ATTR(exp_statsn, ISCSI_EXP_STATSN);
1597         SETUP_CONN_RD_ATTR(persistent_address, ISCSI_PERSISTENT_ADDRESS);
1598         SETUP_CONN_RD_ATTR(persistent_port, ISCSI_PERSISTENT_PORT);
1599         SETUP_CONN_RD_ATTR(ping_tmo, ISCSI_PING_TMO);
1600         SETUP_CONN_RD_ATTR(recv_tmo, ISCSI_RECV_TMO);
1601
1602         BUG_ON(count > ISCSI_CONN_ATTRS);
1603         priv->conn_attrs[count] = NULL;
1604         count = 0;
1605
1606         /* session parameters */
1607         priv->session_cont.ac.attrs = &priv->session_attrs[0];
1608         priv->session_cont.ac.class = &iscsi_session_class.class;
1609         priv->session_cont.ac.match = iscsi_session_match;
1610         transport_container_register(&priv->session_cont);
1611
1612         SETUP_SESSION_RD_ATTR(initial_r2t, ISCSI_INITIAL_R2T_EN);
1613         SETUP_SESSION_RD_ATTR(max_outstanding_r2t, ISCSI_MAX_R2T);
1614         SETUP_SESSION_RD_ATTR(immediate_data, ISCSI_IMM_DATA_EN);
1615         SETUP_SESSION_RD_ATTR(first_burst_len, ISCSI_FIRST_BURST);
1616         SETUP_SESSION_RD_ATTR(max_burst_len, ISCSI_MAX_BURST);
1617         SETUP_SESSION_RD_ATTR(data_pdu_in_order, ISCSI_PDU_INORDER_EN);
1618         SETUP_SESSION_RD_ATTR(data_seq_in_order, ISCSI_DATASEQ_INORDER_EN);
1619         SETUP_SESSION_RD_ATTR(erl, ISCSI_ERL);
1620         SETUP_SESSION_RD_ATTR(targetname, ISCSI_TARGET_NAME);
1621         SETUP_SESSION_RD_ATTR(tpgt, ISCSI_TPGT);
1622         SETUP_SESSION_RD_ATTR(password, ISCSI_USERNAME);
1623         SETUP_SESSION_RD_ATTR(password_in, ISCSI_USERNAME_IN);
1624         SETUP_SESSION_RD_ATTR(username, ISCSI_PASSWORD);
1625         SETUP_SESSION_RD_ATTR(username_in, ISCSI_PASSWORD_IN);
1626         SETUP_SESSION_RD_ATTR(fast_abort, ISCSI_FAST_ABORT);
1627         SETUP_SESSION_RD_ATTR(abort_tmo, ISCSI_ABORT_TMO);
1628         SETUP_SESSION_RD_ATTR(lu_reset_tmo,ISCSI_LU_RESET_TMO);
1629         SETUP_PRIV_SESSION_RD_ATTR(recovery_tmo);
1630         SETUP_PRIV_SESSION_RD_ATTR(state);
1631
1632         BUG_ON(count > ISCSI_SESSION_ATTRS);
1633         priv->session_attrs[count] = NULL;
1634
1635         spin_lock_irqsave(&iscsi_transport_lock, flags);
1636         list_add(&priv->list, &iscsi_transports);
1637         spin_unlock_irqrestore(&iscsi_transport_lock, flags);
1638
1639         printk(KERN_NOTICE "iscsi: registered transport (%s)\n", tt->name);
1640         return &priv->t;
1641
1642 unregister_cdev:
1643         class_device_unregister(&priv->cdev);
1644 free_priv:
1645         kfree(priv);
1646         return NULL;
1647 }
1648 EXPORT_SYMBOL_GPL(iscsi_register_transport);
1649
1650 int iscsi_unregister_transport(struct iscsi_transport *tt)
1651 {
1652         struct iscsi_internal *priv;
1653         unsigned long flags;
1654
1655         BUG_ON(!tt);
1656
1657         mutex_lock(&rx_queue_mutex);
1658
1659         priv = iscsi_if_transport_lookup(tt);
1660         BUG_ON (!priv);
1661
1662         spin_lock_irqsave(&iscsi_transport_lock, flags);
1663         list_del(&priv->list);
1664         spin_unlock_irqrestore(&iscsi_transport_lock, flags);
1665
1666         transport_container_unregister(&priv->conn_cont);
1667         transport_container_unregister(&priv->session_cont);
1668         transport_container_unregister(&priv->t.host_attrs);
1669
1670         sysfs_remove_group(&priv->cdev.kobj, &iscsi_transport_group);
1671         class_device_unregister(&priv->cdev);
1672         mutex_unlock(&rx_queue_mutex);
1673
1674         return 0;
1675 }
1676 EXPORT_SYMBOL_GPL(iscsi_unregister_transport);
1677
1678 static __init int iscsi_transport_init(void)
1679 {
1680         int err;
1681
1682         printk(KERN_INFO "Loading iSCSI transport class v%s.\n",
1683                 ISCSI_TRANSPORT_VERSION);
1684
1685         atomic_set(&iscsi_session_nr, 0);
1686
1687         err = class_register(&iscsi_transport_class);
1688         if (err)
1689                 return err;
1690
1691         err = transport_class_register(&iscsi_host_class);
1692         if (err)
1693                 goto unregister_transport_class;
1694
1695         err = transport_class_register(&iscsi_connection_class);
1696         if (err)
1697                 goto unregister_host_class;
1698
1699         err = transport_class_register(&iscsi_session_class);
1700         if (err)
1701                 goto unregister_conn_class;
1702
1703         nls = netlink_kernel_create(&init_net, NETLINK_ISCSI, 1, iscsi_if_rx, NULL,
1704                         THIS_MODULE);
1705         if (!nls) {
1706                 err = -ENOBUFS;
1707                 goto unregister_session_class;
1708         }
1709
1710         iscsi_eh_timer_workq = create_singlethread_workqueue("iscsi_eh");
1711         if (!iscsi_eh_timer_workq)
1712                 goto release_nls;
1713
1714         return 0;
1715
1716 release_nls:
1717         netlink_kernel_release(nls);
1718 unregister_session_class:
1719         transport_class_unregister(&iscsi_session_class);
1720 unregister_conn_class:
1721         transport_class_unregister(&iscsi_connection_class);
1722 unregister_host_class:
1723         transport_class_unregister(&iscsi_host_class);
1724 unregister_transport_class:
1725         class_unregister(&iscsi_transport_class);
1726         return err;
1727 }
1728
1729 static void __exit iscsi_transport_exit(void)
1730 {
1731         destroy_workqueue(iscsi_eh_timer_workq);
1732         netlink_kernel_release(nls);
1733         transport_class_unregister(&iscsi_connection_class);
1734         transport_class_unregister(&iscsi_session_class);
1735         transport_class_unregister(&iscsi_host_class);
1736         class_unregister(&iscsi_transport_class);
1737 }
1738
1739 module_init(iscsi_transport_init);
1740 module_exit(iscsi_transport_exit);
1741
1742 MODULE_AUTHOR("Mike Christie <michaelc@cs.wisc.edu>, "
1743               "Dmitry Yusupov <dmitry_yus@yahoo.com>, "
1744               "Alex Aizman <itn780@yahoo.com>");
1745 MODULE_DESCRIPTION("iSCSI Transport Interface");
1746 MODULE_LICENSE("GPL");
1747 MODULE_VERSION(ISCSI_TRANSPORT_VERSION);