drivers/scsi/scsi_transport_iscsi.c

   1 /*
   2  * iSCSI transport class definitions
   3  *
   4  * Copyright (C) IBM Corporation, 2004
   5  * Copyright (C) Mike Christie, 2004 - 2005
   6  * Copyright (C) Dmitry Yusupov, 2004 - 2005
   7  * Copyright (C) Alex Aizman, 2004 - 2005
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  22  */
  23 #include <linux/module.h>
  24 #include <linux/mutex.h>
  25 #include <net/tcp.h>
  26 #include <scsi/scsi.h>
  27 #include <scsi/scsi_host.h>
  28 #include <scsi/scsi_device.h>
  29 #include <scsi/scsi_transport.h>
  30 #include <scsi/scsi_transport_iscsi.h>
  31 #include <scsi/iscsi_if.h>
  32
  33 #define ISCSI_SESSION_ATTRS 19
  34 #define ISCSI_CONN_ATTRS 13
  35 #define ISCSI_HOST_ATTRS 4
  36 #define ISCSI_TRANSPORT_VERSION "2.0-869"
  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 device dev;
  44
  45         struct device_attribute *host_attrs[ISCSI_HOST_ATTRS + 1];
  46         struct transport_container conn_cont;
  47         struct device_attribute *conn_attrs[ISCSI_CONN_ATTRS + 1];
  48         struct transport_container session_cont;
  49         struct 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 dev_to_iscsi_internal(_dev) \
  67         container_of(_dev, struct iscsi_internal, dev)
  68
  69 static void iscsi_transport_release(struct device *dev)
  70 {
  71         struct iscsi_internal *priv = dev_to_iscsi_internal(dev);
  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         .dev_release = iscsi_transport_release,
  82 };
  83
  84 static ssize_t
  85 show_transport_handle(struct device *dev, struct device_attribute *attr,
  86                       char *buf)
  87 {
  88         struct iscsi_internal *priv = dev_to_iscsi_internal(dev);
  89         return sprintf(buf, "%llu\n", (unsigned long long)iscsi_handle(priv->iscsi_transport));
  90 }
  91 static DEVICE_ATTR(handle, S_IRUGO, show_transport_handle, NULL);
  92
  93 #define show_transport_attr(name, format)                               \
  94 static ssize_t                                                          \
  95 show_transport_##name(struct device *dev,                               \
  96                       struct device_attribute *attr,char *buf)          \
  97 {                                                                       \
  98         struct iscsi_internal *priv = dev_to_iscsi_internal(dev);       \
  99         return sprintf(buf, format"\n", priv->iscsi_transport->name);   \
 100 }                                                                       \
 101 static DEVICE_ATTR(name, S_IRUGO, show_transport_##name, NULL);
 102
 103 show_transport_attr(caps, "0x%x");
 104 show_transport_attr(max_lun, "%d");
 105 show_transport_attr(max_conn, "%d");
 106 show_transport_attr(max_cmd_len, "%d");
 107
 108 static struct attribute *iscsi_transport_attrs[] = {
 109         &dev_attr_handle.attr,
 110         &dev_attr_caps.attr,
 111         &dev_attr_max_lun.attr,
 112         &dev_attr_max_conn.attr,
 113         &dev_attr_max_cmd_len.attr,
 114         NULL,
 115 };
 116
 117 static struct attribute_group iscsi_transport_group = {
 118         .attrs = iscsi_transport_attrs,
 119 };
 120
 121
 122
 123 static int iscsi_setup_host(struct transport_container *tc, struct device *dev,
 124                             struct device *cdev)
 125 {
 126         struct Scsi_Host *shost = dev_to_shost(dev);
 127         struct iscsi_host *ihost = shost->shost_data;
 128
 129         memset(ihost, 0, sizeof(*ihost));
 130         INIT_LIST_HEAD(&ihost->sessions);
 131         mutex_init(&ihost->mutex);
 132         atomic_set(&ihost->nr_scans, 0);
 133
 134         snprintf(ihost->scan_workq_name, KOBJ_NAME_LEN, "iscsi_scan_%d",
 135                 shost->host_no);
 136         ihost->scan_workq = create_singlethread_workqueue(
 137                                                 ihost->scan_workq_name);
 138         if (!ihost->scan_workq)
 139                 return -ENOMEM;
 140         return 0;
 141 }
 142
 143 static int iscsi_remove_host(struct transport_container *tc, struct device *dev,
 144                              struct device *cdev)
 145 {
 146         struct Scsi_Host *shost = dev_to_shost(dev);
 147         struct iscsi_host *ihost = shost->shost_data;
 148
 149         destroy_workqueue(ihost->scan_workq);
 150         return 0;
 151 }
 152
 153 static DECLARE_TRANSPORT_CLASS(iscsi_host_class,
 154                                "iscsi_host",
 155                                iscsi_setup_host,
 156                                iscsi_remove_host,
 157                                NULL);
 158
 159 static DECLARE_TRANSPORT_CLASS(iscsi_session_class,
 160                                "iscsi_session",
 161                                NULL,
 162                                NULL,
 163                                NULL);
 164
 165 static DECLARE_TRANSPORT_CLASS(iscsi_connection_class,
 166                                "iscsi_connection",
 167                                NULL,
 168                                NULL,
 169                                NULL);
 170
 171 static struct sock *nls;
 172 static DEFINE_MUTEX(rx_queue_mutex);
 173
 174 static LIST_HEAD(sesslist);
 175 static DEFINE_SPINLOCK(sesslock);
 176 static LIST_HEAD(connlist);
 177 static DEFINE_SPINLOCK(connlock);
 178
 179 static uint32_t iscsi_conn_get_sid(struct iscsi_cls_conn *conn)
 180 {
 181         struct iscsi_cls_session *sess = iscsi_dev_to_session(conn->dev.parent);
 182         return sess->sid;
 183 }
 184
 185 /*
 186  * Returns the matching session to a given sid
 187  */
 188 static struct iscsi_cls_session *iscsi_session_lookup(uint32_t sid)
 189 {
 190         unsigned long flags;
 191         struct iscsi_cls_session *sess;
 192
 193         spin_lock_irqsave(&sesslock, flags);
 194         list_for_each_entry(sess, &sesslist, sess_list) {
 195                 if (sess->sid == sid) {
 196                         spin_unlock_irqrestore(&sesslock, flags);
 197                         return sess;
 198                 }
 199         }
 200         spin_unlock_irqrestore(&sesslock, flags);
 201         return NULL;
 202 }
 203
 204 /*
 205  * Returns the matching connection to a given sid / cid tuple
 206  */
 207 static struct iscsi_cls_conn *iscsi_conn_lookup(uint32_t sid, uint32_t cid)
 208 {
 209         unsigned long flags;
 210         struct iscsi_cls_conn *conn;
 211
 212         spin_lock_irqsave(&connlock, flags);
 213         list_for_each_entry(conn, &connlist, conn_list) {
 214                 if ((conn->cid == cid) && (iscsi_conn_get_sid(conn) == sid)) {
 215                         spin_unlock_irqrestore(&connlock, flags);
 216                         return conn;
 217                 }
 218         }
 219         spin_unlock_irqrestore(&connlock, flags);
 220         return NULL;
 221 }
 222
 223 /*
 224  * The following functions can be used by LLDs that allocate
 225  * their own scsi_hosts or by software iscsi LLDs
 226  */
 227 static struct {
 228         int value;
 229         char *name;
 230 } iscsi_session_state_names[] = {
 231         { ISCSI_SESSION_LOGGED_IN,      "LOGGED_IN" },
 232         { ISCSI_SESSION_FAILED,         "FAILED" },
 233         { ISCSI_SESSION_FREE,           "FREE" },
 234 };
 235
 236 static const char *iscsi_session_state_name(int state)
 237 {
 238         int i;
 239         char *name = NULL;
 240
 241         for (i = 0; i < ARRAY_SIZE(iscsi_session_state_names); i++) {
 242                 if (iscsi_session_state_names[i].value == state) {
 243                         name = iscsi_session_state_names[i].name;
 244                         break;
 245                 }
 246         }
 247         return name;
 248 }
 249
 250 int iscsi_session_chkready(struct iscsi_cls_session *session)
 251 {
 252         unsigned long flags;
 253         int err;
 254
 255         spin_lock_irqsave(&session->lock, flags);
 256         switch (session->state) {
 257         case ISCSI_SESSION_LOGGED_IN:
 258                 err = 0;
 259                 break;
 260         case ISCSI_SESSION_FAILED:
 261                 err = DID_IMM_RETRY << 16;
 262                 break;
 263         case ISCSI_SESSION_FREE:
 264                 err = DID_NO_CONNECT << 16;
 265                 break;
 266         default:
 267                 err = DID_NO_CONNECT << 16;
 268                 break;
 269         }
 270         spin_unlock_irqrestore(&session->lock, flags);
 271         return err;
 272 }
 273 EXPORT_SYMBOL_GPL(iscsi_session_chkready);
 274
 275 static void iscsi_session_release(struct device *dev)
 276 {
 277         struct iscsi_cls_session *session = iscsi_dev_to_session(dev);
 278         struct Scsi_Host *shost;
 279
 280         shost = iscsi_session_to_shost(session);
 281         scsi_host_put(shost);
 282         kfree(session);
 283 }
 284
 285 static int iscsi_is_session_dev(const struct device *dev)
 286 {
 287         return dev->release == iscsi_session_release;
 288 }
 289
 290 /**
 291  * iscsi_scan_finished - helper to report when running scans are done
 292  * @shost: scsi host
 293  * @time: scan run time
 294  *
 295  * This function can be used by drives like qla4xxx to report to the scsi
 296  * layer when the scans it kicked off at module load time are done.
 297  */
 298 int iscsi_scan_finished(struct Scsi_Host *shost, unsigned long time)
 299 {
 300         struct iscsi_host *ihost = shost->shost_data;
 301         /*
 302          * qla4xxx will have kicked off some session unblocks before calling
 303          * scsi_scan_host, so just wait for them to complete.
 304          */
 305         return !atomic_read(&ihost->nr_scans);
 306 }
 307 EXPORT_SYMBOL_GPL(iscsi_scan_finished);
 308
 309 static int iscsi_user_scan(struct Scsi_Host *shost, uint channel,
 310                            uint id, uint lun)
 311 {
 312         struct iscsi_host *ihost = shost->shost_data;
 313         struct iscsi_cls_session *session;
 314
 315         mutex_lock(&ihost->mutex);
 316         list_for_each_entry(session, &ihost->sessions, host_list) {
 317                 if ((channel == SCAN_WILD_CARD || channel == 0) &&
 318                     (id == SCAN_WILD_CARD || id == session->target_id))
 319                         scsi_scan_target(&session->dev, 0,
 320                                          session->target_id, lun, 1);
 321         }
 322         mutex_unlock(&ihost->mutex);
 323
 324         return 0;
 325 }
 326
 327 static void iscsi_scan_session(struct work_struct *work)
 328 {
 329         struct iscsi_cls_session *session =
 330                         container_of(work, struct iscsi_cls_session, scan_work);
 331         struct Scsi_Host *shost = iscsi_session_to_shost(session);
 332         struct iscsi_host *ihost = shost->shost_data;
 333         unsigned long flags;
 334
 335         spin_lock_irqsave(&session->lock, flags);
 336         if (session->state != ISCSI_SESSION_LOGGED_IN) {
 337                 spin_unlock_irqrestore(&session->lock, flags);
 338                 goto done;
 339         }
 340         spin_unlock_irqrestore(&session->lock, flags);
 341
 342         scsi_scan_target(&session->dev, 0, session->target_id,
 343                          SCAN_WILD_CARD, 1);
 344 done:
 345         atomic_dec(&ihost->nr_scans);
 346 }
 347
 348 static void session_recovery_timedout(struct work_struct *work)
 349 {
 350         struct iscsi_cls_session *session =
 351                 container_of(work, struct iscsi_cls_session,
 352                              recovery_work.work);
 353         unsigned long flags;
 354
 355         iscsi_cls_session_printk(KERN_INFO, session,
 356                                  "session recovery timed out after %d secs\n",
 357                                  session->recovery_tmo);
 358
 359         spin_lock_irqsave(&session->lock, flags);
 360         switch (session->state) {
 361         case ISCSI_SESSION_FAILED:
 362                 session->state = ISCSI_SESSION_FREE;
 363                 break;
 364         case ISCSI_SESSION_LOGGED_IN:
 365         case ISCSI_SESSION_FREE:
 366                 /* we raced with the unblock's flush */
 367                 spin_unlock_irqrestore(&session->lock, flags);
 368                 return;
 369         }
 370         spin_unlock_irqrestore(&session->lock, flags);
 371
 372         if (session->transport->session_recovery_timedout)
 373                 session->transport->session_recovery_timedout(session);
 374
 375         scsi_target_unblock(&session->dev);
 376 }
 377
 378 static void __iscsi_unblock_session(struct work_struct *work)
 379 {
 380         struct iscsi_cls_session *session =
 381                         container_of(work, struct iscsi_cls_session,
 382                                      unblock_work);
 383         struct Scsi_Host *shost = iscsi_session_to_shost(session);
 384         struct iscsi_host *ihost = shost->shost_data;
 385         unsigned long flags;
 386
 387         /*
 388          * The recovery and unblock work get run from the same workqueue,
 389          * so try to cancel it if it was going to run after this unblock.
 390          */
 391         cancel_delayed_work(&session->recovery_work);
 392         spin_lock_irqsave(&session->lock, flags);
 393         session->state = ISCSI_SESSION_LOGGED_IN;
 394         spin_unlock_irqrestore(&session->lock, flags);
 395         /* start IO */
 396         scsi_target_unblock(&session->dev);
 397         /*
 398          * Only do kernel scanning if the driver is properly hooked into
 399          * the async scanning code (drivers like iscsi_tcp do login and
 400          * scanning from userspace).
 401          */
 402         if (shost->hostt->scan_finished) {
 403                 if (queue_work(ihost->scan_workq, &session->scan_work))
 404                         atomic_inc(&ihost->nr_scans);
 405         }
 406 }
 407
 408 /**
 409  * iscsi_unblock_session - set a session as logged in and start IO.
 410  * @session: iscsi session
 411  *
 412  * Mark a session as ready to accept IO.
 413  */
 414 void iscsi_unblock_session(struct iscsi_cls_session *session)
 415 {
 416         queue_work(iscsi_eh_timer_workq, &session->unblock_work);
 417         /*
 418          * make sure all the events have completed before tell the driver
 419          * it is safe
 420          */
 421         flush_workqueue(iscsi_eh_timer_workq);
 422 }
 423 EXPORT_SYMBOL_GPL(iscsi_unblock_session);
 424
 425 static void __iscsi_block_session(struct work_struct *work)
 426 {
 427         struct iscsi_cls_session *session =
 428                         container_of(work, struct iscsi_cls_session,
 429                                      block_work);
 430         unsigned long flags;
 431
 432         spin_lock_irqsave(&session->lock, flags);
 433         session->state = ISCSI_SESSION_FAILED;
 434         spin_unlock_irqrestore(&session->lock, flags);
 435         scsi_target_block(&session->dev);
 436         queue_delayed_work(iscsi_eh_timer_workq, &session->recovery_work,
 437                            session->recovery_tmo * HZ);
 438 }
 439
 440 void iscsi_block_session(struct iscsi_cls_session *session)
 441 {
 442         queue_work(iscsi_eh_timer_workq, &session->block_work);
 443 }
 444 EXPORT_SYMBOL_GPL(iscsi_block_session);
 445
 446 static void __iscsi_unbind_session(struct work_struct *work)
 447 {
 448         struct iscsi_cls_session *session =
 449                         container_of(work, struct iscsi_cls_session,
 450                                      unbind_work);
 451         struct Scsi_Host *shost = iscsi_session_to_shost(session);
 452         struct iscsi_host *ihost = shost->shost_data;
 453
 454         /* Prevent new scans and make sure scanning is not in progress */
 455         mutex_lock(&ihost->mutex);
 456         if (list_empty(&session->host_list)) {
 457                 mutex_unlock(&ihost->mutex);
 458                 return;
 459         }
 460         list_del_init(&session->host_list);
 461         mutex_unlock(&ihost->mutex);
 462
 463         scsi_remove_target(&session->dev);
 464         iscsi_session_event(session, ISCSI_KEVENT_UNBIND_SESSION);
 465 }
 466
 467 static int iscsi_unbind_session(struct iscsi_cls_session *session)
 468 {
 469         struct Scsi_Host *shost = iscsi_session_to_shost(session);
 470         struct iscsi_host *ihost = shost->shost_data;
 471
 472         return queue_work(ihost->scan_workq, &session->unbind_work);
 473 }
 474
 475 struct iscsi_cls_session *
 476 iscsi_alloc_session(struct Scsi_Host *shost,
 477                     struct iscsi_transport *transport)
 478 {
 479         struct iscsi_cls_session *session;
 480
 481         session = kzalloc(sizeof(*session) + transport->sessiondata_size,
 482                           GFP_KERNEL);
 483         if (!session)
 484                 return NULL;
 485
 486         session->transport = transport;
 487         session->recovery_tmo = 120;
 488         session->state = ISCSI_SESSION_FREE;
 489         INIT_DELAYED_WORK(&session->recovery_work, session_recovery_timedout);
 490         INIT_LIST_HEAD(&session->host_list);
 491         INIT_LIST_HEAD(&session->sess_list);
 492         INIT_WORK(&session->unblock_work, __iscsi_unblock_session);
 493         INIT_WORK(&session->block_work, __iscsi_block_session);
 494         INIT_WORK(&session->unbind_work, __iscsi_unbind_session);
 495         INIT_WORK(&session->scan_work, iscsi_scan_session);
 496         spin_lock_init(&session->lock);
 497
 498         /* this is released in the dev's release function */
 499         scsi_host_get(shost);
 500         session->dev.parent = &shost->shost_gendev;
 501         session->dev.release = iscsi_session_release;
 502         device_initialize(&session->dev);
 503         if (transport->sessiondata_size)
 504                 session->dd_data = &session[1];
 505         return session;
 506 }
 507 EXPORT_SYMBOL_GPL(iscsi_alloc_session);
 508
 509 int iscsi_add_session(struct iscsi_cls_session *session, unsigned int target_id)
 510 {
 511         struct Scsi_Host *shost = iscsi_session_to_shost(session);
 512         struct iscsi_host *ihost;
 513         unsigned long flags;
 514         int err;
 515
 516         ihost = shost->shost_data;
 517         session->sid = atomic_add_return(1, &iscsi_session_nr);
 518         session->target_id = target_id;
 519
 520         snprintf(session->dev.bus_id, BUS_ID_SIZE, "session%u",
 521                  session->sid);
 522         err = device_add(&session->dev);
 523         if (err) {
 524                 iscsi_cls_session_printk(KERN_ERR, session,
 525                                          "could not register session's dev\n");
 526                 goto release_host;
 527         }
 528         transport_register_device(&session->dev);
 529
 530         spin_lock_irqsave(&sesslock, flags);
 531         list_add(&session->sess_list, &sesslist);
 532         spin_unlock_irqrestore(&sesslock, flags);
 533
 534         mutex_lock(&ihost->mutex);
 535         list_add(&session->host_list, &ihost->sessions);
 536         mutex_unlock(&ihost->mutex);
 537
 538         iscsi_session_event(session, ISCSI_KEVENT_CREATE_SESSION);
 539         return 0;
 540
 541 release_host:
 542         scsi_host_put(shost);
 543         return err;
 544 }
 545 EXPORT_SYMBOL_GPL(iscsi_add_session);
 546
 547 /**
 548  * iscsi_create_session - create iscsi class session
 549  * @shost: scsi host
 550  * @transport: iscsi transport
 551  * @target_id: which target
 552  *
 553  * This can be called from a LLD or iscsi_transport.
 554  */
 555 struct iscsi_cls_session *
 556 iscsi_create_session(struct Scsi_Host *shost,
 557                      struct iscsi_transport *transport,
 558                      unsigned int target_id)
 559 {
 560         struct iscsi_cls_session *session;
 561
 562         session = iscsi_alloc_session(shost, transport);
 563         if (!session)
 564                 return NULL;
 565
 566         if (iscsi_add_session(session, target_id)) {
 567                 iscsi_free_session(session);
 568                 return NULL;
 569         }
 570         return session;
 571 }
 572 EXPORT_SYMBOL_GPL(iscsi_create_session);
 573
 574 static void iscsi_conn_release(struct device *dev)
 575 {
 576         struct iscsi_cls_conn *conn = iscsi_dev_to_conn(dev);
 577         struct device *parent = conn->dev.parent;
 578
 579         kfree(conn);
 580         put_device(parent);
 581 }
 582
 583 static int iscsi_is_conn_dev(const struct device *dev)
 584 {
 585         return dev->release == iscsi_conn_release;
 586 }
 587
 588 static int iscsi_iter_destroy_conn_fn(struct device *dev, void *data)
 589 {
 590         if (!iscsi_is_conn_dev(dev))
 591                 return 0;
 592         return iscsi_destroy_conn(iscsi_dev_to_conn(dev));
 593 }
 594
 595 void iscsi_remove_session(struct iscsi_cls_session *session)
 596 {
 597         struct Scsi_Host *shost = iscsi_session_to_shost(session);
 598         struct iscsi_host *ihost = shost->shost_data;
 599         unsigned long flags;
 600         int err;
 601
 602         spin_lock_irqsave(&sesslock, flags);
 603         list_del(&session->sess_list);
 604         spin_unlock_irqrestore(&sesslock, flags);
 605
 606         /* make sure there are no blocks/unblocks queued */
 607         flush_workqueue(iscsi_eh_timer_workq);
 608         /* make sure the timedout callout is not running */
 609         if (!cancel_delayed_work(&session->recovery_work))
 610                 flush_workqueue(iscsi_eh_timer_workq);
 611         /*
 612          * If we are blocked let commands flow again. The lld or iscsi
 613          * layer should set up the queuecommand to fail commands.
 614          * We assume that LLD will not be calling block/unblock while
 615          * removing the session.
 616          */
 617         spin_lock_irqsave(&session->lock, flags);
 618         session->state = ISCSI_SESSION_FREE;
 619         spin_unlock_irqrestore(&session->lock, flags);
 620
 621         scsi_target_unblock(&session->dev);
 622         /* flush running scans then delete devices */
 623         flush_workqueue(ihost->scan_workq);
 624         __iscsi_unbind_session(&session->unbind_work);
 625
 626         /* hw iscsi may not have removed all connections from session */
 627         err = device_for_each_child(&session->dev, NULL,
 628                                     iscsi_iter_destroy_conn_fn);
 629         if (err)
 630                 iscsi_cls_session_printk(KERN_ERR, session,
 631                                          "Could not delete all connections "
 632                                          "for session. Error %d.\n", err);
 633
 634         transport_unregister_device(&session->dev);
 635         device_del(&session->dev);
 636 }
 637 EXPORT_SYMBOL_GPL(iscsi_remove_session);
 638
 639 void iscsi_free_session(struct iscsi_cls_session *session)
 640 {
 641         iscsi_session_event(session, ISCSI_KEVENT_DESTROY_SESSION);
 642         put_device(&session->dev);
 643 }
 644 EXPORT_SYMBOL_GPL(iscsi_free_session);
 645
 646 /**
 647  * iscsi_destroy_session - destroy iscsi session
 648  * @session: iscsi_session
 649  *
 650  * Can be called by a LLD or iscsi_transport. There must not be
 651  * any running connections.
 652  */
 653 int iscsi_destroy_session(struct iscsi_cls_session *session)
 654 {
 655         iscsi_remove_session(session);
 656         iscsi_free_session(session);
 657         return 0;
 658 }
 659 EXPORT_SYMBOL_GPL(iscsi_destroy_session);
 660
 661 /**
 662  * iscsi_create_conn - create iscsi class connection
 663  * @session: iscsi cls session
 664  * @cid: connection id
 665  *
 666  * This can be called from a LLD or iscsi_transport. The connection
 667  * is child of the session so cid must be unique for all connections
 668  * on the session.
 669  *
 670  * Since we do not support MCS, cid will normally be zero. In some cases
 671  * for software iscsi we could be trying to preallocate a connection struct
 672  * in which case there could be two connection structs and cid would be
 673  * non-zero.
 674  */
 675 struct iscsi_cls_conn *
 676 iscsi_create_conn(struct iscsi_cls_session *session, uint32_t cid)
 677 {
 678         struct iscsi_transport *transport = session->transport;
 679         struct iscsi_cls_conn *conn;
 680         unsigned long flags;
 681         int err;
 682
 683         conn = kzalloc(sizeof(*conn) + transport->conndata_size, GFP_KERNEL);
 684         if (!conn)
 685                 return NULL;
 686
 687         if (transport->conndata_size)
 688                 conn->dd_data = &conn[1];
 689
 690         INIT_LIST_HEAD(&conn->conn_list);
 691         conn->transport = transport;
 692         conn->cid = cid;
 693
 694         /* this is released in the dev's release function */
 695         if (!get_device(&session->dev))
 696                 goto free_conn;
 697
 698         snprintf(conn->dev.bus_id, BUS_ID_SIZE, "connection%d:%u",
 699                  session->sid, cid);
 700         conn->dev.parent = &session->dev;
 701         conn->dev.release = iscsi_conn_release;
 702         err = device_register(&conn->dev);
 703         if (err) {
 704                 iscsi_cls_session_printk(KERN_ERR, session, "could not "
 705                                          "register connection's dev\n");
 706                 goto release_parent_ref;
 707         }
 708         transport_register_device(&conn->dev);
 709
 710         spin_lock_irqsave(&connlock, flags);
 711         list_add(&conn->conn_list, &connlist);
 712         conn->active = 1;
 713         spin_unlock_irqrestore(&connlock, flags);
 714         return conn;
 715
 716 release_parent_ref:
 717         put_device(&session->dev);
 718 free_conn:
 719         kfree(conn);
 720         return NULL;
 721 }
 722
 723 EXPORT_SYMBOL_GPL(iscsi_create_conn);
 724
 725 /**
 726  * iscsi_destroy_conn - destroy iscsi class connection
 727  * @conn: iscsi cls session
 728  *
 729  * This can be called from a LLD or iscsi_transport.
 730  */
 731 int iscsi_destroy_conn(struct iscsi_cls_conn *conn)
 732 {
 733         unsigned long flags;
 734
 735         spin_lock_irqsave(&connlock, flags);
 736         conn->active = 0;
 737         list_del(&conn->conn_list);
 738         spin_unlock_irqrestore(&connlock, flags);
 739
 740         transport_unregister_device(&conn->dev);
 741         device_unregister(&conn->dev);
 742         return 0;
 743 }
 744 EXPORT_SYMBOL_GPL(iscsi_destroy_conn);
 745
 746 /*
 747  * iscsi interface functions
 748  */
 749 static struct iscsi_internal *
 750 iscsi_if_transport_lookup(struct iscsi_transport *tt)
 751 {
 752         struct iscsi_internal *priv;
 753         unsigned long flags;
 754
 755         spin_lock_irqsave(&iscsi_transport_lock, flags);
 756         list_for_each_entry(priv, &iscsi_transports, list) {
 757                 if (tt == priv->iscsi_transport) {
 758                         spin_unlock_irqrestore(&iscsi_transport_lock, flags);
 759                         return priv;
 760                 }
 761         }
 762         spin_unlock_irqrestore(&iscsi_transport_lock, flags);
 763         return NULL;
 764 }
 765
 766 static int
 767 iscsi_broadcast_skb(struct sk_buff *skb, gfp_t gfp)
 768 {
 769         int rc;
 770
 771         rc = netlink_broadcast(nls, skb, 0, 1, gfp);
 772         if (rc < 0) {
 773                 printk(KERN_ERR "iscsi: can not broadcast skb (%d)\n", rc);
 774                 return rc;
 775         }
 776
 777         return 0;
 778 }
 779
 780 static int
 781 iscsi_unicast_skb(struct sk_buff *skb, int pid)
 782 {
 783         int rc;
 784
 785         rc = netlink_unicast(nls, skb, pid, MSG_DONTWAIT);
 786         if (rc < 0) {
 787                 printk(KERN_ERR "iscsi: can not unicast skb (%d)\n", rc);
 788                 return rc;
 789         }
 790
 791         return 0;
 792 }
 793
 794 int iscsi_recv_pdu(struct iscsi_cls_conn *conn, struct iscsi_hdr *hdr,
 795                    char *data, uint32_t data_size)
 796 {
 797         struct nlmsghdr *nlh;
 798         struct sk_buff *skb;
 799         struct iscsi_uevent *ev;
 800         char *pdu;
 801         struct iscsi_internal *priv;
 802         int len = NLMSG_SPACE(sizeof(*ev) + sizeof(struct iscsi_hdr) +
 803                               data_size);
 804
 805         priv = iscsi_if_transport_lookup(conn->transport);
 806         if (!priv)
 807                 return -EINVAL;
 808
 809         skb = alloc_skb(len, GFP_ATOMIC);
 810         if (!skb) {
 811                 iscsi_conn_error(conn, ISCSI_ERR_CONN_FAILED);
 812                 iscsi_cls_conn_printk(KERN_ERR, conn, "can not deliver "
 813                                       "control PDU: OOM\n");
 814                 return -ENOMEM;
 815         }
 816
 817         nlh = __nlmsg_put(skb, priv->daemon_pid, 0, 0, (len - sizeof(*nlh)), 0);
 818         ev = NLMSG_DATA(nlh);
 819         memset(ev, 0, sizeof(*ev));
 820         ev->transport_handle = iscsi_handle(conn->transport);
 821         ev->type = ISCSI_KEVENT_RECV_PDU;
 822         ev->r.recv_req.cid = conn->cid;
 823         ev->r.recv_req.sid = iscsi_conn_get_sid(conn);
 824         pdu = (char*)ev + sizeof(*ev);
 825         memcpy(pdu, hdr, sizeof(struct iscsi_hdr));
 826         memcpy(pdu + sizeof(struct iscsi_hdr), data, data_size);
 827
 828         return iscsi_unicast_skb(skb, priv->daemon_pid);
 829 }
 830 EXPORT_SYMBOL_GPL(iscsi_recv_pdu);
 831
 832 void iscsi_conn_error(struct iscsi_cls_conn *conn, enum iscsi_err error)
 833 {
 834         struct nlmsghdr *nlh;
 835         struct sk_buff  *skb;
 836         struct iscsi_uevent *ev;
 837         struct iscsi_internal *priv;
 838         int len = NLMSG_SPACE(sizeof(*ev));
 839
 840         priv = iscsi_if_transport_lookup(conn->transport);
 841         if (!priv)
 842                 return;
 843
 844         skb = alloc_skb(len, GFP_ATOMIC);
 845         if (!skb) {
 846                 iscsi_cls_conn_printk(KERN_ERR, conn, "gracefully ignored "
 847                                       "conn error (%d)\n", error);
 848                 return;
 849         }
 850
 851         nlh = __nlmsg_put(skb, priv->daemon_pid, 0, 0, (len - sizeof(*nlh)), 0);
 852         ev = NLMSG_DATA(nlh);
 853         ev->transport_handle = iscsi_handle(conn->transport);
 854         ev->type = ISCSI_KEVENT_CONN_ERROR;
 855         ev->r.connerror.error = error;
 856         ev->r.connerror.cid = conn->cid;
 857         ev->r.connerror.sid = iscsi_conn_get_sid(conn);
 858
 859         iscsi_broadcast_skb(skb, GFP_ATOMIC);
 860
 861         iscsi_cls_conn_printk(KERN_INFO, conn, "detected conn error (%d)\n",
 862                               error);
 863 }
 864 EXPORT_SYMBOL_GPL(iscsi_conn_error);
 865
 866 static int
 867 iscsi_if_send_reply(int pid, int seq, int type, int done, int multi,
 868                       void *payload, int size)
 869 {
 870         struct sk_buff  *skb;
 871         struct nlmsghdr *nlh;
 872         int len = NLMSG_SPACE(size);
 873         int flags = multi ? NLM_F_MULTI : 0;
 874         int t = done ? NLMSG_DONE : type;
 875
 876         skb = alloc_skb(len, GFP_ATOMIC);
 877         if (!skb) {
 878                 printk(KERN_ERR "Could not allocate skb to send reply.\n");
 879                 return -ENOMEM;
 880         }
 881
 882         nlh = __nlmsg_put(skb, pid, seq, t, (len - sizeof(*nlh)), 0);
 883         nlh->nlmsg_flags = flags;
 884         memcpy(NLMSG_DATA(nlh), payload, size);
 885         return iscsi_unicast_skb(skb, pid);
 886 }
 887
 888 static int
 889 iscsi_if_get_stats(struct iscsi_transport *transport, struct nlmsghdr *nlh)
 890 {
 891         struct iscsi_uevent *ev = NLMSG_DATA(nlh);
 892         struct iscsi_stats *stats;
 893         struct sk_buff *skbstat;
 894         struct iscsi_cls_conn *conn;
 895         struct nlmsghdr *nlhstat;
 896         struct iscsi_uevent *evstat;
 897         struct iscsi_internal *priv;
 898         int len = NLMSG_SPACE(sizeof(*ev) +
 899                               sizeof(struct iscsi_stats) +
 900                               sizeof(struct iscsi_stats_custom) *
 901                               ISCSI_STATS_CUSTOM_MAX);
 902         int err = 0;
 903
 904         priv = iscsi_if_transport_lookup(transport);
 905         if (!priv)
 906                 return -EINVAL;
 907
 908         conn = iscsi_conn_lookup(ev->u.get_stats.sid, ev->u.get_stats.cid);
 909         if (!conn)
 910                 return -EEXIST;
 911
 912         do {
 913                 int actual_size;
 914
 915                 skbstat = alloc_skb(len, GFP_ATOMIC);
 916                 if (!skbstat) {
 917                         iscsi_cls_conn_printk(KERN_ERR, conn, "can not "
 918                                               "deliver stats: OOM\n");
 919                         return -ENOMEM;
 920                 }
 921
 922                 nlhstat = __nlmsg_put(skbstat, priv->daemon_pid, 0, 0,
 923                                       (len - sizeof(*nlhstat)), 0);
 924                 evstat = NLMSG_DATA(nlhstat);
 925                 memset(evstat, 0, sizeof(*evstat));
 926                 evstat->transport_handle = iscsi_handle(conn->transport);
 927                 evstat->type = nlh->nlmsg_type;
 928                 evstat->u.get_stats.cid =
 929                         ev->u.get_stats.cid;
 930                 evstat->u.get_stats.sid =
 931                         ev->u.get_stats.sid;
 932                 stats = (struct iscsi_stats *)
 933                         ((char*)evstat + sizeof(*evstat));
 934                 memset(stats, 0, sizeof(*stats));
 935
 936                 transport->get_stats(conn, stats);
 937                 actual_size = NLMSG_SPACE(sizeof(struct iscsi_uevent) +
 938                                           sizeof(struct iscsi_stats) +
 939                                           sizeof(struct iscsi_stats_custom) *
 940                                           stats->custom_length);
 941                 actual_size -= sizeof(*nlhstat);
 942                 actual_size = NLMSG_LENGTH(actual_size);
 943                 skb_trim(skbstat, NLMSG_ALIGN(actual_size));
 944                 nlhstat->nlmsg_len = actual_size;
 945
 946                 err = iscsi_unicast_skb(skbstat, priv->daemon_pid);
 947         } while (err < 0 && err != -ECONNREFUSED);
 948
 949         return err;
 950 }
 951
 952 /**
 953  * iscsi_session_event - send session destr. completion event
 954  * @session: iscsi class session
 955  * @event: type of event
 956  */
 957 int iscsi_session_event(struct iscsi_cls_session *session,
 958                         enum iscsi_uevent_e event)
 959 {
 960         struct iscsi_internal *priv;
 961         struct Scsi_Host *shost;
 962         struct iscsi_uevent *ev;
 963         struct sk_buff  *skb;
 964         struct nlmsghdr *nlh;
 965         int rc, len = NLMSG_SPACE(sizeof(*ev));
 966
 967         priv = iscsi_if_transport_lookup(session->transport);
 968         if (!priv)
 969                 return -EINVAL;
 970         shost = iscsi_session_to_shost(session);
 971
 972         skb = alloc_skb(len, GFP_KERNEL);
 973         if (!skb) {
 974                 iscsi_cls_session_printk(KERN_ERR, session,
 975                                          "Cannot notify userspace of session "
 976                                          "event %u\n", event);
 977                 return -ENOMEM;
 978         }
 979
 980         nlh = __nlmsg_put(skb, priv->daemon_pid, 0, 0, (len - sizeof(*nlh)), 0);
 981         ev = NLMSG_DATA(nlh);
 982         ev->transport_handle = iscsi_handle(session->transport);
 983
 984         ev->type = event;
 985         switch (event) {
 986         case ISCSI_KEVENT_DESTROY_SESSION:
 987                 ev->r.d_session.host_no = shost->host_no;
 988                 ev->r.d_session.sid = session->sid;
 989                 break;
 990         case ISCSI_KEVENT_CREATE_SESSION:
 991                 ev->r.c_session_ret.host_no = shost->host_no;
 992                 ev->r.c_session_ret.sid = session->sid;
 993                 break;
 994         case ISCSI_KEVENT_UNBIND_SESSION:
 995                 ev->r.unbind_session.host_no = shost->host_no;
 996                 ev->r.unbind_session.sid = session->sid;
 997                 break;
 998         default:
 999                 iscsi_cls_session_printk(KERN_ERR, session, "Invalid event "
1000                                          "%u.\n", event);
1001                 kfree_skb(skb);
1002                 return -EINVAL;
1003         }
1004
1005         /*
1006          * this will occur if the daemon is not up, so we just warn
1007          * the user and when the daemon is restarted it will handle it
1008          */
1009         rc = iscsi_broadcast_skb(skb, GFP_KERNEL);
1010         if (rc < 0)
1011                 iscsi_cls_session_printk(KERN_ERR, session,
1012                                          "Cannot notify userspace of session "
1013                                          "event %u. Check iscsi daemon\n",
1014                                          event);
1015         return rc;
1016 }
1017 EXPORT_SYMBOL_GPL(iscsi_session_event);
1018
1019 static int
1020 iscsi_if_create_session(struct iscsi_internal *priv, struct iscsi_uevent *ev)
1021 {
1022         struct iscsi_transport *transport = priv->iscsi_transport;
1023         struct iscsi_cls_session *session;
1024         uint32_t hostno;
1025
1026         session = transport->create_session(transport, &priv->t,
1027                                             ev->u.c_session.cmds_max,
1028                                             ev->u.c_session.queue_depth,
1029                                             ev->u.c_session.initial_cmdsn,
1030                                             &hostno);
1031         if (!session)
1032                 return -ENOMEM;
1033
1034         ev->r.c_session_ret.host_no = hostno;
1035         ev->r.c_session_ret.sid = session->sid;
1036         return 0;
1037 }
1038
1039 static int
1040 iscsi_if_create_conn(struct iscsi_transport *transport, struct iscsi_uevent *ev)
1041 {
1042         struct iscsi_cls_conn *conn;
1043         struct iscsi_cls_session *session;
1044
1045         session = iscsi_session_lookup(ev->u.c_conn.sid);
1046         if (!session) {
1047                 printk(KERN_ERR "iscsi: invalid session %d.\n",
1048                        ev->u.c_conn.sid);
1049                 return -EINVAL;
1050         }
1051
1052         conn = transport->create_conn(session, ev->u.c_conn.cid);
1053         if (!conn) {
1054                 iscsi_cls_session_printk(KERN_ERR, session,
1055                                          "couldn't create a new connection.");
1056                 return -ENOMEM;
1057         }
1058
1059         ev->r.c_conn_ret.sid = session->sid;
1060         ev->r.c_conn_ret.cid = conn->cid;
1061         return 0;
1062 }
1063
1064 static int
1065 iscsi_if_destroy_conn(struct iscsi_transport *transport, struct iscsi_uevent *ev)
1066 {
1067         struct iscsi_cls_conn *conn;
1068
1069         conn = iscsi_conn_lookup(ev->u.d_conn.sid, ev->u.d_conn.cid);
1070         if (!conn)
1071                 return -EINVAL;
1072
1073         if (transport->destroy_conn)
1074                 transport->destroy_conn(conn);
1075         return 0;
1076 }
1077
1078 static int
1079 iscsi_set_param(struct iscsi_transport *transport, struct iscsi_uevent *ev)
1080 {
1081         char *data = (char*)ev + sizeof(*ev);
1082         struct iscsi_cls_conn *conn;
1083         struct iscsi_cls_session *session;
1084         int err = 0, value = 0;
1085
1086         session = iscsi_session_lookup(ev->u.set_param.sid);
1087         conn = iscsi_conn_lookup(ev->u.set_param.sid, ev->u.set_param.cid);
1088         if (!conn || !session)
1089                 return -EINVAL;
1090
1091         switch (ev->u.set_param.param) {
1092         case ISCSI_PARAM_SESS_RECOVERY_TMO:
1093                 sscanf(data, "%d", &value);
1094                 if (value != 0)
1095                         session->recovery_tmo = value;
1096                 break;
1097         default:
1098                 err = transport->set_param(conn, ev->u.set_param.param,
1099                                            data, ev->u.set_param.len);
1100         }
1101
1102         return err;
1103 }
1104
1105 static int
1106 iscsi_if_transport_ep(struct iscsi_transport *transport,
1107                       struct iscsi_uevent *ev, int msg_type)
1108 {
1109         struct sockaddr *dst_addr;
1110         int rc = 0;
1111
1112         switch (msg_type) {
1113         case ISCSI_UEVENT_TRANSPORT_EP_CONNECT:
1114                 if (!transport->ep_connect)
1115                         return -EINVAL;
1116
1117                 dst_addr = (struct sockaddr *)((char*)ev + sizeof(*ev));
1118                 rc = transport->ep_connect(dst_addr,
1119                                            ev->u.ep_connect.non_blocking,
1120                                            &ev->r.ep_connect_ret.handle);
1121                 break;
1122         case ISCSI_UEVENT_TRANSPORT_EP_POLL:
1123                 if (!transport->ep_poll)
1124                         return -EINVAL;
1125
1126                 ev->r.retcode = transport->ep_poll(ev->u.ep_poll.ep_handle,
1127                                                    ev->u.ep_poll.timeout_ms);
1128                 break;
1129         case ISCSI_UEVENT_TRANSPORT_EP_DISCONNECT:
1130                 if (!transport->ep_disconnect)
1131                         return -EINVAL;
1132
1133                 transport->ep_disconnect(ev->u.ep_disconnect.ep_handle);
1134                 break;
1135         }
1136         return rc;
1137 }
1138
1139 static int
1140 iscsi_tgt_dscvr(struct iscsi_transport *transport,
1141                 struct iscsi_uevent *ev)
1142 {
1143         struct Scsi_Host *shost;
1144         struct sockaddr *dst_addr;
1145         int err;
1146
1147         if (!transport->tgt_dscvr)
1148                 return -EINVAL;
1149
1150         shost = scsi_host_lookup(ev->u.tgt_dscvr.host_no);
1151         if (IS_ERR(shost)) {
1152                 printk(KERN_ERR "target discovery could not find host no %u\n",
1153                        ev->u.tgt_dscvr.host_no);
1154                 return -ENODEV;
1155         }
1156
1157
1158         dst_addr = (struct sockaddr *)((char*)ev + sizeof(*ev));
1159         err = transport->tgt_dscvr(shost, ev->u.tgt_dscvr.type,
1160                                    ev->u.tgt_dscvr.enable, dst_addr);
1161         scsi_host_put(shost);
1162         return err;
1163 }
1164
1165 static int
1166 iscsi_set_host_param(struct iscsi_transport *transport,
1167                      struct iscsi_uevent *ev)
1168 {
1169         char *data = (char*)ev + sizeof(*ev);
1170         struct Scsi_Host *shost;
1171         int err;
1172
1173         if (!transport->set_host_param)
1174                 return -ENOSYS;
1175
1176         shost = scsi_host_lookup(ev->u.set_host_param.host_no);
1177         if (IS_ERR(shost)) {
1178                 printk(KERN_ERR "set_host_param could not find host no %u\n",
1179                        ev->u.set_host_param.host_no);
1180                 return -ENODEV;
1181         }
1182
1183         err = transport->set_host_param(shost, ev->u.set_host_param.param,
1184                                         data, ev->u.set_host_param.len);
1185         scsi_host_put(shost);
1186         return err;
1187 }
1188
1189 static int
1190 iscsi_if_recv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
1191 {
1192         int err = 0;
1193         struct iscsi_uevent *ev = NLMSG_DATA(nlh);
1194         struct iscsi_transport *transport = NULL;
1195         struct iscsi_internal *priv;
1196         struct iscsi_cls_session *session;
1197         struct iscsi_cls_conn *conn;
1198
1199         priv = iscsi_if_transport_lookup(iscsi_ptr(ev->transport_handle));
1200         if (!priv)
1201                 return -EINVAL;
1202         transport = priv->iscsi_transport;
1203
1204         if (!try_module_get(transport->owner))
1205                 return -EINVAL;
1206
1207         priv->daemon_pid = NETLINK_CREDS(skb)->pid;
1208
1209         switch (nlh->nlmsg_type) {
1210         case ISCSI_UEVENT_CREATE_SESSION:
1211                 err = iscsi_if_create_session(priv, ev);
1212                 break;
1213         case ISCSI_UEVENT_DESTROY_SESSION:
1214                 session = iscsi_session_lookup(ev->u.d_session.sid);
1215                 if (session)
1216                         transport->destroy_session(session);
1217                 else
1218                         err = -EINVAL;
1219                 break;
1220         case ISCSI_UEVENT_UNBIND_SESSION:
1221                 session = iscsi_session_lookup(ev->u.d_session.sid);
1222                 if (session)
1223                         iscsi_unbind_session(session);
1224                 else
1225                         err = -EINVAL;
1226                 break;
1227         case ISCSI_UEVENT_CREATE_CONN:
1228                 err = iscsi_if_create_conn(transport, ev);
1229                 break;
1230         case ISCSI_UEVENT_DESTROY_CONN:
1231                 err = iscsi_if_destroy_conn(transport, ev);
1232                 break;
1233         case ISCSI_UEVENT_BIND_CONN:
1234                 session = iscsi_session_lookup(ev->u.b_conn.sid);
1235                 conn = iscsi_conn_lookup(ev->u.b_conn.sid, ev->u.b_conn.cid);
1236
1237                 if (session && conn)
1238                         ev->r.retcode = transport->bind_conn(session, conn,
1239                                         ev->u.b_conn.transport_eph,
1240                                         ev->u.b_conn.is_leading);
1241                 else
1242                         err = -EINVAL;
1243                 break;
1244         case ISCSI_UEVENT_SET_PARAM:
1245                 err = iscsi_set_param(transport, ev);
1246                 break;
1247         case ISCSI_UEVENT_START_CONN:
1248                 conn = iscsi_conn_lookup(ev->u.start_conn.sid, ev->u.start_conn.cid);
1249                 if (conn)
1250                         ev->r.retcode = transport->start_conn(conn);
1251                 else
1252                         err = -EINVAL;
1253                 break;
1254         case ISCSI_UEVENT_STOP_CONN:
1255                 conn = iscsi_conn_lookup(ev->u.stop_conn.sid, ev->u.stop_conn.cid);
1256                 if (conn)
1257                         transport->stop_conn(conn, ev->u.stop_conn.flag);
1258                 else
1259                         err = -EINVAL;
1260                 break;
1261         case ISCSI_UEVENT_SEND_PDU:
1262                 conn = iscsi_conn_lookup(ev->u.send_pdu.sid, ev->u.send_pdu.cid);
1263                 if (conn)
1264                         ev->r.retcode = transport->send_pdu(conn,
1265                                 (struct iscsi_hdr*)((char*)ev + sizeof(*ev)),
1266                                 (char*)ev + sizeof(*ev) + ev->u.send_pdu.hdr_size,
1267                                 ev->u.send_pdu.data_size);
1268                 else
1269                         err = -EINVAL;
1270                 break;
1271         case ISCSI_UEVENT_GET_STATS:
1272                 err = iscsi_if_get_stats(transport, nlh);
1273                 break;
1274         case ISCSI_UEVENT_TRANSPORT_EP_CONNECT:
1275         case ISCSI_UEVENT_TRANSPORT_EP_POLL:
1276         case ISCSI_UEVENT_TRANSPORT_EP_DISCONNECT:
1277                 err = iscsi_if_transport_ep(transport, ev, nlh->nlmsg_type);
1278                 break;
1279         case ISCSI_UEVENT_TGT_DSCVR:
1280                 err = iscsi_tgt_dscvr(transport, ev);
1281                 break;
1282         case ISCSI_UEVENT_SET_HOST_PARAM:
1283                 err = iscsi_set_host_param(transport, ev);
1284                 break;
1285         default:
1286                 err = -ENOSYS;
1287                 break;
1288         }
1289
1290         module_put(transport->owner);
1291         return err;
1292 }
1293
1294 /*
1295  * Get message from skb.  Each message is processed by iscsi_if_recv_msg.
1296  * Malformed skbs with wrong lengths or invalid creds are not processed.
1297  */
1298 static void
1299 iscsi_if_rx(struct sk_buff *skb)
1300 {
1301         mutex_lock(&rx_queue_mutex);
1302         while (skb->len >= NLMSG_SPACE(0)) {
1303                 int err;
1304                 uint32_t rlen;
1305                 struct nlmsghdr *nlh;
1306                 struct iscsi_uevent *ev;
1307
1308                 nlh = nlmsg_hdr(skb);
1309                 if (nlh->nlmsg_len < sizeof(*nlh) ||
1310                     skb->len < nlh->nlmsg_len) {
1311                         break;
1312                 }
1313
1314                 ev = NLMSG_DATA(nlh);
1315                 rlen = NLMSG_ALIGN(nlh->nlmsg_len);
1316                 if (rlen > skb->len)
1317                         rlen = skb->len;
1318
1319                 err = iscsi_if_recv_msg(skb, nlh);
1320                 if (err) {
1321                         ev->type = ISCSI_KEVENT_IF_ERROR;
1322                         ev->iferror = err;
1323                 }
1324                 do {
1325                         /*
1326                          * special case for GET_STATS:
1327                          * on success - sending reply and stats from
1328                          * inside of if_recv_msg(),
1329                          * on error - fall through.
1330                          */
1331                         if (ev->type == ISCSI_UEVENT_GET_STATS && !err)
1332                                 break;
1333                         err = iscsi_if_send_reply(
1334                                 NETLINK_CREDS(skb)->pid, nlh->nlmsg_seq,
1335                                 nlh->nlmsg_type, 0, 0, ev, sizeof(*ev));
1336                 } while (err < 0 && err != -ECONNREFUSED);
1337                 skb_pull(skb, rlen);
1338         }
1339         mutex_unlock(&rx_queue_mutex);
1340 }
1341
1342 #define ISCSI_CLASS_ATTR(_prefix,_name,_mode,_show,_store)              \
1343 struct device_attribute dev_attr_##_prefix##_##_name =  \
1344         __ATTR(_name,_mode,_show,_store)
1345
1346 /*
1347  * iSCSI connection attrs
1348  */
1349 #define iscsi_conn_attr_show(param)                                     \
1350 static ssize_t                                                          \
1351 show_conn_param_##param(struct device *dev,                             \
1352                         struct device_attribute *attr, char *buf)       \
1353 {                                                                       \
1354         struct iscsi_cls_conn *conn = iscsi_dev_to_conn(dev->parent);   \
1355         struct iscsi_transport *t = conn->transport;                    \
1356         return t->get_conn_param(conn, param, buf);                     \
1357 }
1358
1359 #define iscsi_conn_attr(field, param)                                   \
1360         iscsi_conn_attr_show(param)                                     \
1361 static ISCSI_CLASS_ATTR(conn, field, S_IRUGO, show_conn_param_##param,  \
1362                         NULL);
1363
1364 iscsi_conn_attr(max_recv_dlength, ISCSI_PARAM_MAX_RECV_DLENGTH);
1365 iscsi_conn_attr(max_xmit_dlength, ISCSI_PARAM_MAX_XMIT_DLENGTH);
1366 iscsi_conn_attr(header_digest, ISCSI_PARAM_HDRDGST_EN);
1367 iscsi_conn_attr(data_digest, ISCSI_PARAM_DATADGST_EN);
1368 iscsi_conn_attr(ifmarker, ISCSI_PARAM_IFMARKER_EN);
1369 iscsi_conn_attr(ofmarker, ISCSI_PARAM_OFMARKER_EN);
1370 iscsi_conn_attr(persistent_port, ISCSI_PARAM_PERSISTENT_PORT);
1371 iscsi_conn_attr(port, ISCSI_PARAM_CONN_PORT);
1372 iscsi_conn_attr(exp_statsn, ISCSI_PARAM_EXP_STATSN);
1373 iscsi_conn_attr(persistent_address, ISCSI_PARAM_PERSISTENT_ADDRESS);
1374 iscsi_conn_attr(address, ISCSI_PARAM_CONN_ADDRESS);
1375 iscsi_conn_attr(ping_tmo, ISCSI_PARAM_PING_TMO);
1376 iscsi_conn_attr(recv_tmo, ISCSI_PARAM_RECV_TMO);
1377
1378 /*
1379  * iSCSI session attrs
1380  */
1381 #define iscsi_session_attr_show(param, perm)                            \
1382 static ssize_t                                                          \
1383 show_session_param_##param(struct device *dev,                          \
1384                            struct device_attribute *attr, char *buf)    \
1385 {                                                                       \
1386         struct iscsi_cls_session *session =                             \
1387                 iscsi_dev_to_session(dev->parent);                      \
1388         struct iscsi_transport *t = session->transport;                 \
1389                                                                         \
1390         if (perm && !capable(CAP_SYS_ADMIN))                            \
1391                 return -EACCES;                                         \
1392         return t->get_session_param(session, param, buf);               \
1393 }
1394
1395 #define iscsi_session_attr(field, param, perm)                          \
1396         iscsi_session_attr_show(param, perm)                            \
1397 static ISCSI_CLASS_ATTR(sess, field, S_IRUGO, show_session_param_##param, \
1398                         NULL);
1399
1400 iscsi_session_attr(targetname, ISCSI_PARAM_TARGET_NAME, 0);
1401 iscsi_session_attr(initial_r2t, ISCSI_PARAM_INITIAL_R2T_EN, 0);
1402 iscsi_session_attr(max_outstanding_r2t, ISCSI_PARAM_MAX_R2T, 0);
1403 iscsi_session_attr(immediate_data, ISCSI_PARAM_IMM_DATA_EN, 0);
1404 iscsi_session_attr(first_burst_len, ISCSI_PARAM_FIRST_BURST, 0);
1405 iscsi_session_attr(max_burst_len, ISCSI_PARAM_MAX_BURST, 0);
1406 iscsi_session_attr(data_pdu_in_order, ISCSI_PARAM_PDU_INORDER_EN, 0);
1407 iscsi_session_attr(data_seq_in_order, ISCSI_PARAM_DATASEQ_INORDER_EN, 0);
1408 iscsi_session_attr(erl, ISCSI_PARAM_ERL, 0);
1409 iscsi_session_attr(tpgt, ISCSI_PARAM_TPGT, 0);
1410 iscsi_session_attr(username, ISCSI_PARAM_USERNAME, 1);
1411 iscsi_session_attr(username_in, ISCSI_PARAM_USERNAME_IN, 1);
1412 iscsi_session_attr(password, ISCSI_PARAM_PASSWORD, 1);
1413 iscsi_session_attr(password_in, ISCSI_PARAM_PASSWORD_IN, 1);
1414 iscsi_session_attr(fast_abort, ISCSI_PARAM_FAST_ABORT, 0);
1415 iscsi_session_attr(abort_tmo, ISCSI_PARAM_ABORT_TMO, 0);
1416 iscsi_session_attr(lu_reset_tmo, ISCSI_PARAM_LU_RESET_TMO, 0);
1417
1418 static ssize_t
1419 show_priv_session_state(struct device *dev, struct device_attribute *attr,
1420                         char *buf)
1421 {
1422         struct iscsi_cls_session *session = iscsi_dev_to_session(dev->parent);
1423         return sprintf(buf, "%s\n", iscsi_session_state_name(session->state));
1424 }
1425 static ISCSI_CLASS_ATTR(priv_sess, state, S_IRUGO, show_priv_session_state,
1426                         NULL);
1427
1428 #define iscsi_priv_session_attr_show(field, format)                     \
1429 static ssize_t                                                          \
1430 show_priv_session_##field(struct device *dev,                           \
1431                           struct device_attribute *attr, char *buf)     \
1432 {                                                                       \
1433         struct iscsi_cls_session *session =                             \
1434                         iscsi_dev_to_session(dev->parent);              \
1435         return sprintf(buf, format"\n", session->field);                \
1436 }
1437
1438 #define iscsi_priv_session_attr(field, format)                          \
1439         iscsi_priv_session_attr_show(field, format)                     \
1440 static ISCSI_CLASS_ATTR(priv_sess, field, S_IRUGO, show_priv_session_##field, \
1441                         NULL)
1442 iscsi_priv_session_attr(recovery_tmo, "%d");
1443
1444 /*
1445  * iSCSI host attrs
1446  */
1447 #define iscsi_host_attr_show(param)                                     \
1448 static ssize_t                                                          \
1449 show_host_param_##param(struct device *dev,                             \
1450                         struct device_attribute *attr, char *buf)       \
1451 {                                                                       \
1452         struct Scsi_Host *shost = transport_class_to_shost(dev);        \
1453         struct iscsi_internal *priv = to_iscsi_internal(shost->transportt); \
1454         return priv->iscsi_transport->get_host_param(shost, param, buf); \
1455 }
1456
1457 #define iscsi_host_attr(field, param)                                   \
1458         iscsi_host_attr_show(param)                                     \
1459 static ISCSI_CLASS_ATTR(host, field, S_IRUGO, show_host_param_##param,  \
1460                         NULL);
1461
1462 iscsi_host_attr(netdev, ISCSI_HOST_PARAM_NETDEV_NAME);
1463 iscsi_host_attr(hwaddress, ISCSI_HOST_PARAM_HWADDRESS);
1464 iscsi_host_attr(ipaddress, ISCSI_HOST_PARAM_IPADDRESS);
1465 iscsi_host_attr(initiatorname, ISCSI_HOST_PARAM_INITIATOR_NAME);
1466
1467 #define SETUP_PRIV_SESSION_RD_ATTR(field)                               \
1468 do {                                                                    \
1469         priv->session_attrs[count] = &dev_attr_priv_sess_##field; \
1470         count++;                                                        \
1471 } while (0)
1472
1473
1474 #define SETUP_SESSION_RD_ATTR(field, param_flag)                        \
1475 do {                                                                    \
1476         if (tt->param_mask & param_flag) {                              \
1477                 priv->session_attrs[count] = &dev_attr_sess_##field; \
1478                 count++;                                                \
1479         }                                                               \
1480 } while (0)
1481
1482 #define SETUP_CONN_RD_ATTR(field, param_flag)                           \
1483 do {                                                                    \
1484         if (tt->param_mask & param_flag) {                              \
1485                 priv->conn_attrs[count] = &dev_attr_conn_##field; \
1486                 count++;                                                \
1487         }                                                               \
1488 } while (0)
1489
1490 #define SETUP_HOST_RD_ATTR(field, param_flag)                           \
1491 do {                                                                    \
1492         if (tt->host_param_mask & param_flag) {                         \
1493                 priv->host_attrs[count] = &dev_attr_host_##field; \
1494                 count++;                                                \
1495         }                                                               \
1496 } while (0)
1497
1498 static int iscsi_session_match(struct attribute_container *cont,
1499                            struct device *dev)
1500 {
1501         struct iscsi_cls_session *session;
1502         struct Scsi_Host *shost;
1503         struct iscsi_internal *priv;
1504
1505         if (!iscsi_is_session_dev(dev))
1506                 return 0;
1507
1508         session = iscsi_dev_to_session(dev);
1509         shost = iscsi_session_to_shost(session);
1510         if (!shost->transportt)
1511                 return 0;
1512
1513         priv = to_iscsi_internal(shost->transportt);
1514         if (priv->session_cont.ac.class != &iscsi_session_class.class)
1515                 return 0;
1516
1517         return &priv->session_cont.ac == cont;
1518 }
1519
1520 static int iscsi_conn_match(struct attribute_container *cont,
1521                            struct device *dev)
1522 {
1523         struct iscsi_cls_session *session;
1524         struct iscsi_cls_conn *conn;
1525         struct Scsi_Host *shost;
1526         struct iscsi_internal *priv;
1527
1528         if (!iscsi_is_conn_dev(dev))
1529                 return 0;
1530
1531         conn = iscsi_dev_to_conn(dev);
1532         session = iscsi_dev_to_session(conn->dev.parent);
1533         shost = iscsi_session_to_shost(session);
1534
1535         if (!shost->transportt)
1536                 return 0;
1537
1538         priv = to_iscsi_internal(shost->transportt);
1539         if (priv->conn_cont.ac.class != &iscsi_connection_class.class)
1540                 return 0;
1541
1542         return &priv->conn_cont.ac == cont;
1543 }
1544
1545 static int iscsi_host_match(struct attribute_container *cont,
1546                             struct device *dev)
1547 {
1548         struct Scsi_Host *shost;
1549         struct iscsi_internal *priv;
1550
1551         if (!scsi_is_host_device(dev))
1552                 return 0;
1553
1554         shost = dev_to_shost(dev);
1555         if (!shost->transportt  ||
1556             shost->transportt->host_attrs.ac.class != &iscsi_host_class.class)
1557                 return 0;
1558
1559         priv = to_iscsi_internal(shost->transportt);
1560         return &priv->t.host_attrs.ac == cont;
1561 }
1562
1563 struct scsi_transport_template *
1564 iscsi_register_transport(struct iscsi_transport *tt)
1565 {
1566         struct iscsi_internal *priv;
1567         unsigned long flags;
1568         int count = 0, err;
1569
1570         BUG_ON(!tt);
1571
1572         priv = iscsi_if_transport_lookup(tt);
1573         if (priv)
1574                 return NULL;
1575
1576         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
1577         if (!priv)
1578                 return NULL;
1579         INIT_LIST_HEAD(&priv->list);
1580         priv->daemon_pid = -1;
1581         priv->iscsi_transport = tt;
1582         priv->t.user_scan = iscsi_user_scan;
1583
1584         priv->dev.class = &iscsi_transport_class;
1585         snprintf(priv->dev.bus_id, BUS_ID_SIZE, "%s", tt->name);
1586         err = device_register(&priv->dev);
1587         if (err)
1588                 goto free_priv;
1589
1590         err = sysfs_create_group(&priv->dev.kobj, &iscsi_transport_group);
1591         if (err)
1592                 goto unregister_dev;
1593
1594         /* host parameters */
1595         priv->t.host_attrs.ac.attrs = &priv->host_attrs[0];
1596         priv->t.host_attrs.ac.class = &iscsi_host_class.class;
1597         priv->t.host_attrs.ac.match = iscsi_host_match;
1598         priv->t.host_size = sizeof(struct iscsi_host);
1599         transport_container_register(&priv->t.host_attrs);
1600
1601         SETUP_HOST_RD_ATTR(netdev, ISCSI_HOST_NETDEV_NAME);
1602         SETUP_HOST_RD_ATTR(ipaddress, ISCSI_HOST_IPADDRESS);
1603         SETUP_HOST_RD_ATTR(hwaddress, ISCSI_HOST_HWADDRESS);
1604         SETUP_HOST_RD_ATTR(initiatorname, ISCSI_HOST_INITIATOR_NAME);
1605         BUG_ON(count > ISCSI_HOST_ATTRS);
1606         priv->host_attrs[count] = NULL;
1607         count = 0;
1608
1609         /* connection parameters */
1610         priv->conn_cont.ac.attrs = &priv->conn_attrs[0];
1611         priv->conn_cont.ac.class = &iscsi_connection_class.class;
1612         priv->conn_cont.ac.match = iscsi_conn_match;
1613         transport_container_register(&priv->conn_cont);
1614
1615         SETUP_CONN_RD_ATTR(max_recv_dlength, ISCSI_MAX_RECV_DLENGTH);
1616         SETUP_CONN_RD_ATTR(max_xmit_dlength, ISCSI_MAX_XMIT_DLENGTH);
1617         SETUP_CONN_RD_ATTR(header_digest, ISCSI_HDRDGST_EN);
1618         SETUP_CONN_RD_ATTR(data_digest, ISCSI_DATADGST_EN);
1619         SETUP_CONN_RD_ATTR(ifmarker, ISCSI_IFMARKER_EN);
1620         SETUP_CONN_RD_ATTR(ofmarker, ISCSI_OFMARKER_EN);
1621         SETUP_CONN_RD_ATTR(address, ISCSI_CONN_ADDRESS);
1622         SETUP_CONN_RD_ATTR(port, ISCSI_CONN_PORT);
1623         SETUP_CONN_RD_ATTR(exp_statsn, ISCSI_EXP_STATSN);
1624         SETUP_CONN_RD_ATTR(persistent_address, ISCSI_PERSISTENT_ADDRESS);
1625         SETUP_CONN_RD_ATTR(persistent_port, ISCSI_PERSISTENT_PORT);
1626         SETUP_CONN_RD_ATTR(ping_tmo, ISCSI_PING_TMO);
1627         SETUP_CONN_RD_ATTR(recv_tmo, ISCSI_RECV_TMO);
1628
1629         BUG_ON(count > ISCSI_CONN_ATTRS);
1630         priv->conn_attrs[count] = NULL;
1631         count = 0;
1632
1633         /* session parameters */
1634         priv->session_cont.ac.attrs = &priv->session_attrs[0];
1635         priv->session_cont.ac.class = &iscsi_session_class.class;
1636         priv->session_cont.ac.match = iscsi_session_match;
1637         transport_container_register(&priv->session_cont);
1638
1639         SETUP_SESSION_RD_ATTR(initial_r2t, ISCSI_INITIAL_R2T_EN);
1640         SETUP_SESSION_RD_ATTR(max_outstanding_r2t, ISCSI_MAX_R2T);
1641         SETUP_SESSION_RD_ATTR(immediate_data, ISCSI_IMM_DATA_EN);
1642         SETUP_SESSION_RD_ATTR(first_burst_len, ISCSI_FIRST_BURST);
1643         SETUP_SESSION_RD_ATTR(max_burst_len, ISCSI_MAX_BURST);
1644         SETUP_SESSION_RD_ATTR(data_pdu_in_order, ISCSI_PDU_INORDER_EN);
1645         SETUP_SESSION_RD_ATTR(data_seq_in_order, ISCSI_DATASEQ_INORDER_EN);
1646         SETUP_SESSION_RD_ATTR(erl, ISCSI_ERL);
1647         SETUP_SESSION_RD_ATTR(targetname, ISCSI_TARGET_NAME);
1648         SETUP_SESSION_RD_ATTR(tpgt, ISCSI_TPGT);
1649         SETUP_SESSION_RD_ATTR(password, ISCSI_USERNAME);
1650         SETUP_SESSION_RD_ATTR(password_in, ISCSI_USERNAME_IN);
1651         SETUP_SESSION_RD_ATTR(username, ISCSI_PASSWORD);
1652         SETUP_SESSION_RD_ATTR(username_in, ISCSI_PASSWORD_IN);
1653         SETUP_SESSION_RD_ATTR(fast_abort, ISCSI_FAST_ABORT);
1654         SETUP_SESSION_RD_ATTR(abort_tmo, ISCSI_ABORT_TMO);
1655         SETUP_SESSION_RD_ATTR(lu_reset_tmo,ISCSI_LU_RESET_TMO);
1656         SETUP_PRIV_SESSION_RD_ATTR(recovery_tmo);
1657         SETUP_PRIV_SESSION_RD_ATTR(state);
1658
1659         BUG_ON(count > ISCSI_SESSION_ATTRS);
1660         priv->session_attrs[count] = NULL;
1661
1662         spin_lock_irqsave(&iscsi_transport_lock, flags);
1663         list_add(&priv->list, &iscsi_transports);
1664         spin_unlock_irqrestore(&iscsi_transport_lock, flags);
1665
1666         printk(KERN_NOTICE "iscsi: registered transport (%s)\n", tt->name);
1667         return &priv->t;
1668
1669 unregister_dev:
1670         device_unregister(&priv->dev);
1671 free_priv:
1672         kfree(priv);
1673         return NULL;
1674 }
1675 EXPORT_SYMBOL_GPL(iscsi_register_transport);
1676
1677 int iscsi_unregister_transport(struct iscsi_transport *tt)
1678 {
1679         struct iscsi_internal *priv;
1680         unsigned long flags;
1681
1682         BUG_ON(!tt);
1683
1684         mutex_lock(&rx_queue_mutex);
1685
1686         priv = iscsi_if_transport_lookup(tt);
1687         BUG_ON (!priv);
1688
1689         spin_lock_irqsave(&iscsi_transport_lock, flags);
1690         list_del(&priv->list);
1691         spin_unlock_irqrestore(&iscsi_transport_lock, flags);
1692
1693         transport_container_unregister(&priv->conn_cont);
1694         transport_container_unregister(&priv->session_cont);
1695         transport_container_unregister(&priv->t.host_attrs);
1696
1697         sysfs_remove_group(&priv->dev.kobj, &iscsi_transport_group);
1698         device_unregister(&priv->dev);
1699         mutex_unlock(&rx_queue_mutex);
1700
1701         return 0;
1702 }
1703 EXPORT_SYMBOL_GPL(iscsi_unregister_transport);
1704
1705 static __init int iscsi_transport_init(void)
1706 {
1707         int err;
1708
1709         printk(KERN_INFO "Loading iSCSI transport class v%s.\n",
1710                 ISCSI_TRANSPORT_VERSION);
1711
1712         atomic_set(&iscsi_session_nr, 0);
1713
1714         err = class_register(&iscsi_transport_class);
1715         if (err)
1716                 return err;
1717
1718         err = transport_class_register(&iscsi_host_class);
1719         if (err)
1720                 goto unregister_transport_class;
1721
1722         err = transport_class_register(&iscsi_connection_class);
1723         if (err)
1724                 goto unregister_host_class;
1725
1726         err = transport_class_register(&iscsi_session_class);
1727         if (err)
1728                 goto unregister_conn_class;
1729
1730         nls = netlink_kernel_create(&init_net, NETLINK_ISCSI, 1, iscsi_if_rx, NULL,
1731                         THIS_MODULE);
1732         if (!nls) {
1733                 err = -ENOBUFS;
1734                 goto unregister_session_class;
1735         }
1736
1737         iscsi_eh_timer_workq = create_singlethread_workqueue("iscsi_eh");
1738         if (!iscsi_eh_timer_workq)
1739                 goto release_nls;
1740
1741         return 0;
1742
1743 release_nls:
1744         netlink_kernel_release(nls);
1745 unregister_session_class:
1746         transport_class_unregister(&iscsi_session_class);
1747 unregister_conn_class:
1748         transport_class_unregister(&iscsi_connection_class);
1749 unregister_host_class:
1750         transport_class_unregister(&iscsi_host_class);
1751 unregister_transport_class:
1752         class_unregister(&iscsi_transport_class);
1753         return err;
1754 }
1755
1756 static void __exit iscsi_transport_exit(void)
1757 {
1758         destroy_workqueue(iscsi_eh_timer_workq);
1759         netlink_kernel_release(nls);
1760         transport_class_unregister(&iscsi_connection_class);
1761         transport_class_unregister(&iscsi_session_class);
1762         transport_class_unregister(&iscsi_host_class);
1763         class_unregister(&iscsi_transport_class);
1764 }
1765
1766 module_init(iscsi_transport_init);
1767 module_exit(iscsi_transport_exit);
1768
1769 MODULE_AUTHOR("Mike Christie <michaelc@cs.wisc.edu>, "
1770               "Dmitry Yusupov <dmitry_yus@yahoo.com>, "
1771               "Alex Aizman <itn780@yahoo.com>");
1772 MODULE_DESCRIPTION("iSCSI Transport Interface");
1773 MODULE_LICENSE("GPL");
1774 MODULE_VERSION(ISCSI_TRANSPORT_VERSION);