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