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 <linux/slab.h>
  26 #include <net/tcp.h>
  27 #include <scsi/scsi.h>
  28 #include <scsi/scsi_host.h>
  29 #include <scsi/scsi_device.h>
  30 #include <scsi/scsi_transport.h>
  31 #include <scsi/scsi_transport_iscsi.h>
  32 #include <scsi/iscsi_if.h>
  33 #include <scsi/scsi_cmnd.h>
  34
  35 #define ISCSI_SESSION_ATTRS 23
  36 #define ISCSI_CONN_ATTRS 13
  37 #define ISCSI_HOST_ATTRS 4
  38
  39 #define ISCSI_TRANSPORT_VERSION "2.0-870"
  40
  41 static int dbg_session;
  42 module_param_named(debug_session, dbg_session, int,
  43                    S_IRUGO | S_IWUSR);
  44 MODULE_PARM_DESC(debug_session,
  45                  "Turn on debugging for sessions in scsi_transport_iscsi "
  46                  "module. Set to 1 to turn on, and zero to turn off. Default "
  47                  "is off.");
  48
  49 static int dbg_conn;
  50 module_param_named(debug_conn, dbg_conn, int,
  51                    S_IRUGO | S_IWUSR);
  52 MODULE_PARM_DESC(debug_conn,
  53                  "Turn on debugging for connections in scsi_transport_iscsi "
  54                  "module. Set to 1 to turn on, and zero to turn off. Default "
  55                  "is off.");
  56
  57 #define ISCSI_DBG_TRANS_SESSION(_session, dbg_fmt, arg...)              \
  58         do {                                                            \
  59                 if (dbg_session)                                        \
  60                         iscsi_cls_session_printk(KERN_INFO, _session,   \
  61                                                  "%s: " dbg_fmt,        \
  62                                                  __func__, ##arg);      \
  63         } while (0);
  64
  65 #define ISCSI_DBG_TRANS_CONN(_conn, dbg_fmt, arg...)                    \
  66         do {                                                            \
  67                 if (dbg_conn)                                           \
  68                         iscsi_cls_conn_printk(KERN_INFO, _conn,         \
  69                                               "%s: " dbg_fmt,           \
  70                                               __func__, ##arg); \
  71         } while (0);
  72
  73 struct iscsi_internal {
  74         struct scsi_transport_template t;
  75         struct iscsi_transport *iscsi_transport;
  76         struct list_head list;
  77         struct device dev;
  78
  79         struct device_attribute *host_attrs[ISCSI_HOST_ATTRS + 1];
  80         struct transport_container conn_cont;
  81         struct device_attribute *conn_attrs[ISCSI_CONN_ATTRS + 1];
  82         struct transport_container session_cont;
  83         struct device_attribute *session_attrs[ISCSI_SESSION_ATTRS + 1];
  84 };
  85
  86 static atomic_t iscsi_session_nr; /* sysfs session id for next new session */
  87 static struct workqueue_struct *iscsi_eh_timer_workq;
  88
  89 /*
  90  * list of registered transports and lock that must
  91  * be held while accessing list. The iscsi_transport_lock must
  92  * be acquired after the rx_queue_mutex.
  93  */
  94 static LIST_HEAD(iscsi_transports);
  95 static DEFINE_SPINLOCK(iscsi_transport_lock);
  96
  97 #define to_iscsi_internal(tmpl) \
  98         container_of(tmpl, struct iscsi_internal, t)
  99
 100 #define dev_to_iscsi_internal(_dev) \
 101         container_of(_dev, struct iscsi_internal, dev)
 102
 103 static void iscsi_transport_release(struct device *dev)
 104 {
 105         struct iscsi_internal *priv = dev_to_iscsi_internal(dev);
 106         kfree(priv);
 107 }
 108
 109 /*
 110  * iscsi_transport_class represents the iscsi_transports that are
 111  * registered.
 112  */
 113 static struct class iscsi_transport_class = {
 114         .name = "iscsi_transport",
 115         .dev_release = iscsi_transport_release,
 116 };
 117
 118 static ssize_t
 119 show_transport_handle(struct device *dev, struct device_attribute *attr,
 120                       char *buf)
 121 {
 122         struct iscsi_internal *priv = dev_to_iscsi_internal(dev);
 123         return sprintf(buf, "%llu\n", (unsigned long long)iscsi_handle(priv->iscsi_transport));
 124 }
 125 static DEVICE_ATTR(handle, S_IRUGO, show_transport_handle, NULL);
 126
 127 #define show_transport_attr(name, format)                               \
 128 static ssize_t                                                          \
 129 show_transport_##name(struct device *dev,                               \
 130                       struct device_attribute *attr,char *buf)          \
 131 {                                                                       \
 132         struct iscsi_internal *priv = dev_to_iscsi_internal(dev);       \
 133         return sprintf(buf, format"\n", priv->iscsi_transport->name);   \
 134 }                                                                       \
 135 static DEVICE_ATTR(name, S_IRUGO, show_transport_##name, NULL);
 136
 137 show_transport_attr(caps, "0x%x");
 138
 139 static struct attribute *iscsi_transport_attrs[] = {
 140         &dev_attr_handle.attr,
 141         &dev_attr_caps.attr,
 142         NULL,
 143 };
 144
 145 static struct attribute_group iscsi_transport_group = {
 146         .attrs = iscsi_transport_attrs,
 147 };
 148
 149 /*
 150  * iSCSI endpoint attrs
 151  */
 152 #define iscsi_dev_to_endpoint(_dev) \
 153         container_of(_dev, struct iscsi_endpoint, dev)
 154
 155 #define ISCSI_ATTR(_prefix,_name,_mode,_show,_store)    \
 156 struct device_attribute dev_attr_##_prefix##_##_name =  \
 157         __ATTR(_name,_mode,_show,_store)
 158
 159 static void iscsi_endpoint_release(struct device *dev)
 160 {
 161         struct iscsi_endpoint *ep = iscsi_dev_to_endpoint(dev);
 162         kfree(ep);
 163 }
 164
 165 static struct class iscsi_endpoint_class = {
 166         .name = "iscsi_endpoint",
 167         .dev_release = iscsi_endpoint_release,
 168 };
 169
 170 static ssize_t
 171 show_ep_handle(struct device *dev, struct device_attribute *attr, char *buf)
 172 {
 173         struct iscsi_endpoint *ep = iscsi_dev_to_endpoint(dev);
 174         return sprintf(buf, "%llu\n", (unsigned long long) ep->id);
 175 }
 176 static ISCSI_ATTR(ep, handle, S_IRUGO, show_ep_handle, NULL);
 177
 178 static struct attribute *iscsi_endpoint_attrs[] = {
 179         &dev_attr_ep_handle.attr,
 180         NULL,
 181 };
 182
 183 static struct attribute_group iscsi_endpoint_group = {
 184         .attrs = iscsi_endpoint_attrs,
 185 };
 186
 187 #define ISCSI_MAX_EPID -1
 188
 189 static int iscsi_match_epid(struct device *dev, void *data)
 190 {
 191         struct iscsi_endpoint *ep = iscsi_dev_to_endpoint(dev);
 192         uint64_t *epid = (uint64_t *) data;
 193
 194         return *epid == ep->id;
 195 }
 196
 197 struct iscsi_endpoint *
 198 iscsi_create_endpoint(int dd_size)
 199 {
 200         struct device *dev;
 201         struct iscsi_endpoint *ep;
 202         uint64_t id;
 203         int err;
 204
 205         for (id = 1; id < ISCSI_MAX_EPID; id++) {
 206                 dev = class_find_device(&iscsi_endpoint_class, NULL, &id,
 207                                         iscsi_match_epid);
 208                 if (!dev)
 209                         break;
 210         }
 211         if (id == ISCSI_MAX_EPID) {
 212                 printk(KERN_ERR "Too many connections. Max supported %u\n",
 213                        ISCSI_MAX_EPID - 1);
 214                 return NULL;
 215         }
 216
 217         ep = kzalloc(sizeof(*ep) + dd_size, GFP_KERNEL);
 218         if (!ep)
 219                 return NULL;
 220
 221         ep->id = id;
 222         ep->dev.class = &iscsi_endpoint_class;
 223         dev_set_name(&ep->dev, "ep-%llu", (unsigned long long) id);
 224         err = device_register(&ep->dev);
 225         if (err)
 226                 goto free_ep;
 227
 228         err = sysfs_create_group(&ep->dev.kobj, &iscsi_endpoint_group);
 229         if (err)
 230                 goto unregister_dev;
 231
 232         if (dd_size)
 233                 ep->dd_data = &ep[1];
 234         return ep;
 235
 236 unregister_dev:
 237         device_unregister(&ep->dev);
 238         return NULL;
 239
 240 free_ep:
 241         kfree(ep);
 242         return NULL;
 243 }
 244 EXPORT_SYMBOL_GPL(iscsi_create_endpoint);
 245
 246 void iscsi_destroy_endpoint(struct iscsi_endpoint *ep)
 247 {
 248         sysfs_remove_group(&ep->dev.kobj, &iscsi_endpoint_group);
 249         device_unregister(&ep->dev);
 250 }
 251 EXPORT_SYMBOL_GPL(iscsi_destroy_endpoint);
 252
 253 struct iscsi_endpoint *iscsi_lookup_endpoint(u64 handle)
 254 {
 255         struct iscsi_endpoint *ep;
 256         struct device *dev;
 257
 258         dev = class_find_device(&iscsi_endpoint_class, NULL, &handle,
 259                                 iscsi_match_epid);
 260         if (!dev)
 261                 return NULL;
 262
 263         ep = iscsi_dev_to_endpoint(dev);
 264         /*
 265          * we can drop this now because the interface will prevent
 266          * removals and lookups from racing.
 267          */
 268         put_device(dev);
 269         return ep;
 270 }
 271 EXPORT_SYMBOL_GPL(iscsi_lookup_endpoint);
 272
 273 static int iscsi_setup_host(struct transport_container *tc, struct device *dev,
 274                             struct device *cdev)
 275 {
 276         struct Scsi_Host *shost = dev_to_shost(dev);
 277         struct iscsi_cls_host *ihost = shost->shost_data;
 278
 279         memset(ihost, 0, sizeof(*ihost));
 280         atomic_set(&ihost->nr_scans, 0);
 281         mutex_init(&ihost->mutex);
 282         return 0;
 283 }
 284
 285 static DECLARE_TRANSPORT_CLASS(iscsi_host_class,
 286                                "iscsi_host",
 287                                iscsi_setup_host,
 288                                NULL,
 289                                NULL);
 290
 291 static DECLARE_TRANSPORT_CLASS(iscsi_session_class,
 292                                "iscsi_session",
 293                                NULL,
 294                                NULL,
 295                                NULL);
 296
 297 static DECLARE_TRANSPORT_CLASS(iscsi_connection_class,
 298                                "iscsi_connection",
 299                                NULL,
 300                                NULL,
 301                                NULL);
 302
 303 static struct sock *nls;
 304 static DEFINE_MUTEX(rx_queue_mutex);
 305
 306 static LIST_HEAD(sesslist);
 307 static DEFINE_SPINLOCK(sesslock);
 308 static LIST_HEAD(connlist);
 309 static DEFINE_SPINLOCK(connlock);
 310
 311 static uint32_t iscsi_conn_get_sid(struct iscsi_cls_conn *conn)
 312 {
 313         struct iscsi_cls_session *sess = iscsi_dev_to_session(conn->dev.parent);
 314         return sess->sid;
 315 }
 316
 317 /*
 318  * Returns the matching session to a given sid
 319  */
 320 static struct iscsi_cls_session *iscsi_session_lookup(uint32_t sid)
 321 {
 322         unsigned long flags;
 323         struct iscsi_cls_session *sess;
 324
 325         spin_lock_irqsave(&sesslock, flags);
 326         list_for_each_entry(sess, &sesslist, sess_list) {
 327                 if (sess->sid == sid) {
 328                         spin_unlock_irqrestore(&sesslock, flags);
 329                         return sess;
 330                 }
 331         }
 332         spin_unlock_irqrestore(&sesslock, flags);
 333         return NULL;
 334 }
 335
 336 /*
 337  * Returns the matching connection to a given sid / cid tuple
 338  */
 339 static struct iscsi_cls_conn *iscsi_conn_lookup(uint32_t sid, uint32_t cid)
 340 {
 341         unsigned long flags;
 342         struct iscsi_cls_conn *conn;
 343
 344         spin_lock_irqsave(&connlock, flags);
 345         list_for_each_entry(conn, &connlist, conn_list) {
 346                 if ((conn->cid == cid) && (iscsi_conn_get_sid(conn) == sid)) {
 347                         spin_unlock_irqrestore(&connlock, flags);
 348                         return conn;
 349                 }
 350         }
 351         spin_unlock_irqrestore(&connlock, flags);
 352         return NULL;
 353 }
 354
 355 /*
 356  * The following functions can be used by LLDs that allocate
 357  * their own scsi_hosts or by software iscsi LLDs
 358  */
 359 static struct {
 360         int value;
 361         char *name;
 362 } iscsi_session_state_names[] = {
 363         { ISCSI_SESSION_LOGGED_IN,      "LOGGED_IN" },
 364         { ISCSI_SESSION_FAILED,         "FAILED" },
 365         { ISCSI_SESSION_FREE,           "FREE" },
 366 };
 367
 368 static const char *iscsi_session_state_name(int state)
 369 {
 370         int i;
 371         char *name = NULL;
 372
 373         for (i = 0; i < ARRAY_SIZE(iscsi_session_state_names); i++) {
 374                 if (iscsi_session_state_names[i].value == state) {
 375                         name = iscsi_session_state_names[i].name;
 376                         break;
 377                 }
 378         }
 379         return name;
 380 }
 381
 382 int iscsi_session_chkready(struct iscsi_cls_session *session)
 383 {
 384         unsigned long flags;
 385         int err;
 386
 387         spin_lock_irqsave(&session->lock, flags);
 388         switch (session->state) {
 389         case ISCSI_SESSION_LOGGED_IN:
 390                 err = 0;
 391                 break;
 392         case ISCSI_SESSION_FAILED:
 393                 err = DID_IMM_RETRY << 16;
 394                 break;
 395         case ISCSI_SESSION_FREE:
 396                 err = DID_TRANSPORT_FAILFAST << 16;
 397                 break;
 398         default:
 399                 err = DID_NO_CONNECT << 16;
 400                 break;
 401         }
 402         spin_unlock_irqrestore(&session->lock, flags);
 403         return err;
 404 }
 405 EXPORT_SYMBOL_GPL(iscsi_session_chkready);
 406
 407 static void iscsi_session_release(struct device *dev)
 408 {
 409         struct iscsi_cls_session *session = iscsi_dev_to_session(dev);
 410         struct Scsi_Host *shost;
 411
 412         shost = iscsi_session_to_shost(session);
 413         scsi_host_put(shost);
 414         ISCSI_DBG_TRANS_SESSION(session, "Completing session release\n");
 415         kfree(session);
 416 }
 417
 418 static int iscsi_is_session_dev(const struct device *dev)
 419 {
 420         return dev->release == iscsi_session_release;
 421 }
 422
 423 static int iscsi_iter_session_fn(struct device *dev, void *data)
 424 {
 425         void (* fn) (struct iscsi_cls_session *) = data;
 426
 427         if (!iscsi_is_session_dev(dev))
 428                 return 0;
 429         fn(iscsi_dev_to_session(dev));
 430         return 0;
 431 }
 432
 433 void iscsi_host_for_each_session(struct Scsi_Host *shost,
 434                                  void (*fn)(struct iscsi_cls_session *))
 435 {
 436         device_for_each_child(&shost->shost_gendev, fn,
 437                               iscsi_iter_session_fn);
 438 }
 439 EXPORT_SYMBOL_GPL(iscsi_host_for_each_session);
 440
 441 /**
 442  * iscsi_scan_finished - helper to report when running scans are done
 443  * @shost: scsi host
 444  * @time: scan run time
 445  *
 446  * This function can be used by drives like qla4xxx to report to the scsi
 447  * layer when the scans it kicked off at module load time are done.
 448  */
 449 int iscsi_scan_finished(struct Scsi_Host *shost, unsigned long time)
 450 {
 451         struct iscsi_cls_host *ihost = shost->shost_data;
 452         /*
 453          * qla4xxx will have kicked off some session unblocks before calling
 454          * scsi_scan_host, so just wait for them to complete.
 455          */
 456         return !atomic_read(&ihost->nr_scans);
 457 }
 458 EXPORT_SYMBOL_GPL(iscsi_scan_finished);
 459
 460 struct iscsi_scan_data {
 461         unsigned int channel;
 462         unsigned int id;
 463         unsigned int lun;
 464 };
 465
 466 static int iscsi_user_scan_session(struct device *dev, void *data)
 467 {
 468         struct iscsi_scan_data *scan_data = data;
 469         struct iscsi_cls_session *session;
 470         struct Scsi_Host *shost;
 471         struct iscsi_cls_host *ihost;
 472         unsigned long flags;
 473         unsigned int id;
 474
 475         if (!iscsi_is_session_dev(dev))
 476                 return 0;
 477
 478         session = iscsi_dev_to_session(dev);
 479
 480         ISCSI_DBG_TRANS_SESSION(session, "Scanning session\n");
 481
 482         shost = iscsi_session_to_shost(session);
 483         ihost = shost->shost_data;
 484
 485         mutex_lock(&ihost->mutex);
 486         spin_lock_irqsave(&session->lock, flags);
 487         if (session->state != ISCSI_SESSION_LOGGED_IN) {
 488                 spin_unlock_irqrestore(&session->lock, flags);
 489                 goto user_scan_exit;
 490         }
 491         id = session->target_id;
 492         spin_unlock_irqrestore(&session->lock, flags);
 493
 494         if (id != ISCSI_MAX_TARGET) {
 495                 if ((scan_data->channel == SCAN_WILD_CARD ||
 496                      scan_data->channel == 0) &&
 497                     (scan_data->id == SCAN_WILD_CARD ||
 498                      scan_data->id == id))
 499                         scsi_scan_target(&session->dev, 0, id,
 500                                          scan_data->lun, 1);
 501         }
 502
 503 user_scan_exit:
 504         mutex_unlock(&ihost->mutex);
 505         ISCSI_DBG_TRANS_SESSION(session, "Completed session scan\n");
 506         return 0;
 507 }
 508
 509 static int iscsi_user_scan(struct Scsi_Host *shost, uint channel,
 510                            uint id, uint lun)
 511 {
 512         struct iscsi_scan_data scan_data;
 513
 514         scan_data.channel = channel;
 515         scan_data.id = id;
 516         scan_data.lun = lun;
 517
 518         return device_for_each_child(&shost->shost_gendev, &scan_data,
 519                                      iscsi_user_scan_session);
 520 }
 521
 522 static void iscsi_scan_session(struct work_struct *work)
 523 {
 524         struct iscsi_cls_session *session =
 525                         container_of(work, struct iscsi_cls_session, scan_work);
 526         struct Scsi_Host *shost = iscsi_session_to_shost(session);
 527         struct iscsi_cls_host *ihost = shost->shost_data;
 528         struct iscsi_scan_data scan_data;
 529
 530         scan_data.channel = 0;
 531         scan_data.id = SCAN_WILD_CARD;
 532         scan_data.lun = SCAN_WILD_CARD;
 533
 534         iscsi_user_scan_session(&session->dev, &scan_data);
 535         atomic_dec(&ihost->nr_scans);
 536 }
 537
 538 /**
 539  * iscsi_block_scsi_eh - block scsi eh until session state has transistioned
 540  * @cmd: scsi cmd passed to scsi eh handler
 541  *
 542  * If the session is down this function will wait for the recovery
 543  * timer to fire or for the session to be logged back in. If the
 544  * recovery timer fires then FAST_IO_FAIL is returned. The caller
 545  * should pass this error value to the scsi eh.
 546  */
 547 int iscsi_block_scsi_eh(struct scsi_cmnd *cmd)
 548 {
 549         struct iscsi_cls_session *session =
 550                         starget_to_session(scsi_target(cmd->device));
 551         unsigned long flags;
 552         int ret = 0;
 553
 554         spin_lock_irqsave(&session->lock, flags);
 555         while (session->state != ISCSI_SESSION_LOGGED_IN) {
 556                 if (session->state == ISCSI_SESSION_FREE) {
 557                         ret = FAST_IO_FAIL;
 558                         break;
 559                 }
 560                 spin_unlock_irqrestore(&session->lock, flags);
 561                 msleep(1000);
 562                 spin_lock_irqsave(&session->lock, flags);
 563         }
 564         spin_unlock_irqrestore(&session->lock, flags);
 565         return ret;
 566 }
 567 EXPORT_SYMBOL_GPL(iscsi_block_scsi_eh);
 568
 569 static void session_recovery_timedout(struct work_struct *work)
 570 {
 571         struct iscsi_cls_session *session =
 572                 container_of(work, struct iscsi_cls_session,
 573                              recovery_work.work);
 574         unsigned long flags;
 575
 576         iscsi_cls_session_printk(KERN_INFO, session,
 577                                  "session recovery timed out after %d secs\n",
 578                                  session->recovery_tmo);
 579
 580         spin_lock_irqsave(&session->lock, flags);
 581         switch (session->state) {
 582         case ISCSI_SESSION_FAILED:
 583                 session->state = ISCSI_SESSION_FREE;
 584                 break;
 585         case ISCSI_SESSION_LOGGED_IN:
 586         case ISCSI_SESSION_FREE:
 587                 /* we raced with the unblock's flush */
 588                 spin_unlock_irqrestore(&session->lock, flags);
 589                 return;
 590         }
 591         spin_unlock_irqrestore(&session->lock, flags);
 592
 593         if (session->transport->session_recovery_timedout)
 594                 session->transport->session_recovery_timedout(session);
 595
 596         ISCSI_DBG_TRANS_SESSION(session, "Unblocking SCSI target\n");
 597         scsi_target_unblock(&session->dev);
 598         ISCSI_DBG_TRANS_SESSION(session, "Completed unblocking SCSI target\n");
 599 }
 600
 601 static void __iscsi_unblock_session(struct work_struct *work)
 602 {
 603         struct iscsi_cls_session *session =
 604                         container_of(work, struct iscsi_cls_session,
 605                                      unblock_work);
 606         struct Scsi_Host *shost = iscsi_session_to_shost(session);
 607         struct iscsi_cls_host *ihost = shost->shost_data;
 608         unsigned long flags;
 609
 610         ISCSI_DBG_TRANS_SESSION(session, "Unblocking session\n");
 611         /*
 612          * The recovery and unblock work get run from the same workqueue,
 613          * so try to cancel it if it was going to run after this unblock.
 614          */
 615         cancel_delayed_work(&session->recovery_work);
 616         spin_lock_irqsave(&session->lock, flags);
 617         session->state = ISCSI_SESSION_LOGGED_IN;
 618         spin_unlock_irqrestore(&session->lock, flags);
 619         /* start IO */
 620         scsi_target_unblock(&session->dev);
 621         /*
 622          * Only do kernel scanning if the driver is properly hooked into
 623          * the async scanning code (drivers like iscsi_tcp do login and
 624          * scanning from userspace).
 625          */
 626         if (shost->hostt->scan_finished) {
 627                 if (scsi_queue_work(shost, &session->scan_work))
 628                         atomic_inc(&ihost->nr_scans);
 629         }
 630         ISCSI_DBG_TRANS_SESSION(session, "Completed unblocking session\n");
 631 }
 632
 633 /**
 634  * iscsi_unblock_session - set a session as logged in and start IO.
 635  * @session: iscsi session
 636  *
 637  * Mark a session as ready to accept IO.
 638  */
 639 void iscsi_unblock_session(struct iscsi_cls_session *session)
 640 {
 641         queue_work(iscsi_eh_timer_workq, &session->unblock_work);
 642         /*
 643          * make sure all the events have completed before tell the driver
 644          * it is safe
 645          */
 646         flush_workqueue(iscsi_eh_timer_workq);
 647 }
 648 EXPORT_SYMBOL_GPL(iscsi_unblock_session);
 649
 650 static void __iscsi_block_session(struct work_struct *work)
 651 {
 652         struct iscsi_cls_session *session =
 653                         container_of(work, struct iscsi_cls_session,
 654                                      block_work);
 655         unsigned long flags;
 656
 657         ISCSI_DBG_TRANS_SESSION(session, "Blocking session\n");
 658         spin_lock_irqsave(&session->lock, flags);
 659         session->state = ISCSI_SESSION_FAILED;
 660         spin_unlock_irqrestore(&session->lock, flags);
 661         scsi_target_block(&session->dev);
 662         ISCSI_DBG_TRANS_SESSION(session, "Completed SCSI target blocking\n");
 663         if (session->recovery_tmo >= 0)
 664                 queue_delayed_work(iscsi_eh_timer_workq,
 665                                    &session->recovery_work,
 666                                    session->recovery_tmo * HZ);
 667 }
 668
 669 void iscsi_block_session(struct iscsi_cls_session *session)
 670 {
 671         queue_work(iscsi_eh_timer_workq, &session->block_work);
 672 }
 673 EXPORT_SYMBOL_GPL(iscsi_block_session);
 674
 675 static void __iscsi_unbind_session(struct work_struct *work)
 676 {
 677         struct iscsi_cls_session *session =
 678                         container_of(work, struct iscsi_cls_session,
 679                                      unbind_work);
 680         struct Scsi_Host *shost = iscsi_session_to_shost(session);
 681         struct iscsi_cls_host *ihost = shost->shost_data;
 682         unsigned long flags;
 683
 684         ISCSI_DBG_TRANS_SESSION(session, "Unbinding session\n");
 685
 686         /* Prevent new scans and make sure scanning is not in progress */
 687         mutex_lock(&ihost->mutex);
 688         spin_lock_irqsave(&session->lock, flags);
 689         if (session->target_id == ISCSI_MAX_TARGET) {
 690                 spin_unlock_irqrestore(&session->lock, flags);
 691                 mutex_unlock(&ihost->mutex);
 692                 return;
 693         }
 694         session->target_id = ISCSI_MAX_TARGET;
 695         spin_unlock_irqrestore(&session->lock, flags);
 696         mutex_unlock(&ihost->mutex);
 697
 698         scsi_remove_target(&session->dev);
 699         iscsi_session_event(session, ISCSI_KEVENT_UNBIND_SESSION);
 700         ISCSI_DBG_TRANS_SESSION(session, "Completed target removal\n");
 701 }
 702
 703 struct iscsi_cls_session *
 704 iscsi_alloc_session(struct Scsi_Host *shost, struct iscsi_transport *transport,
 705                     int dd_size)
 706 {
 707         struct iscsi_cls_session *session;
 708
 709         session = kzalloc(sizeof(*session) + dd_size,
 710                           GFP_KERNEL);
 711         if (!session)
 712                 return NULL;
 713
 714         session->transport = transport;
 715         session->recovery_tmo = 120;
 716         session->state = ISCSI_SESSION_FREE;
 717         INIT_DELAYED_WORK(&session->recovery_work, session_recovery_timedout);
 718         INIT_LIST_HEAD(&session->sess_list);
 719         INIT_WORK(&session->unblock_work, __iscsi_unblock_session);
 720         INIT_WORK(&session->block_work, __iscsi_block_session);
 721         INIT_WORK(&session->unbind_work, __iscsi_unbind_session);
 722         INIT_WORK(&session->scan_work, iscsi_scan_session);
 723         spin_lock_init(&session->lock);
 724
 725         /* this is released in the dev's release function */
 726         scsi_host_get(shost);
 727         session->dev.parent = &shost->shost_gendev;
 728         session->dev.release = iscsi_session_release;
 729         device_initialize(&session->dev);
 730         if (dd_size)
 731                 session->dd_data = &session[1];
 732
 733         ISCSI_DBG_TRANS_SESSION(session, "Completed session allocation\n");
 734         return session;
 735 }
 736 EXPORT_SYMBOL_GPL(iscsi_alloc_session);
 737
 738 static int iscsi_get_next_target_id(struct device *dev, void *data)
 739 {
 740         struct iscsi_cls_session *session;
 741         unsigned long flags;
 742         int err = 0;
 743
 744         if (!iscsi_is_session_dev(dev))
 745                 return 0;
 746
 747         session = iscsi_dev_to_session(dev);
 748         spin_lock_irqsave(&session->lock, flags);
 749         if (*((unsigned int *) data) == session->target_id)
 750                 err = -EEXIST;
 751         spin_unlock_irqrestore(&session->lock, flags);
 752         return err;
 753 }
 754
 755 int iscsi_add_session(struct iscsi_cls_session *session, unsigned int target_id)
 756 {
 757         struct Scsi_Host *shost = iscsi_session_to_shost(session);
 758         struct iscsi_cls_host *ihost;
 759         unsigned long flags;
 760         unsigned int id = target_id;
 761         int err;
 762
 763         ihost = shost->shost_data;
 764         session->sid = atomic_add_return(1, &iscsi_session_nr);
 765
 766         if (id == ISCSI_MAX_TARGET) {
 767                 for (id = 0; id < ISCSI_MAX_TARGET; id++) {
 768                         err = device_for_each_child(&shost->shost_gendev, &id,
 769                                                     iscsi_get_next_target_id);
 770                         if (!err)
 771                                 break;
 772                 }
 773
 774                 if (id == ISCSI_MAX_TARGET) {
 775                         iscsi_cls_session_printk(KERN_ERR, session,
 776                                                  "Too many iscsi targets. Max "
 777                                                  "number of targets is %d.\n",
 778                                                  ISCSI_MAX_TARGET - 1);
 779                         err = -EOVERFLOW;
 780                         goto release_host;
 781                 }
 782         }
 783         session->target_id = id;
 784
 785         dev_set_name(&session->dev, "session%u", session->sid);
 786         err = device_add(&session->dev);
 787         if (err) {
 788                 iscsi_cls_session_printk(KERN_ERR, session,
 789                                          "could not register session's dev\n");
 790                 goto release_host;
 791         }
 792         transport_register_device(&session->dev);
 793
 794         spin_lock_irqsave(&sesslock, flags);
 795         list_add(&session->sess_list, &sesslist);
 796         spin_unlock_irqrestore(&sesslock, flags);
 797
 798         iscsi_session_event(session, ISCSI_KEVENT_CREATE_SESSION);
 799         ISCSI_DBG_TRANS_SESSION(session, "Completed session adding\n");
 800         return 0;
 801
 802 release_host:
 803         scsi_host_put(shost);
 804         return err;
 805 }
 806 EXPORT_SYMBOL_GPL(iscsi_add_session);
 807
 808 /**
 809  * iscsi_create_session - create iscsi class session
 810  * @shost: scsi host
 811  * @transport: iscsi transport
 812  * @dd_size: private driver data size
 813  * @target_id: which target
 814  *
 815  * This can be called from a LLD or iscsi_transport.
 816  */
 817 struct iscsi_cls_session *
 818 iscsi_create_session(struct Scsi_Host *shost, struct iscsi_transport *transport,
 819                      int dd_size, unsigned int target_id)
 820 {
 821         struct iscsi_cls_session *session;
 822
 823         session = iscsi_alloc_session(shost, transport, dd_size);
 824         if (!session)
 825                 return NULL;
 826
 827         if (iscsi_add_session(session, target_id)) {
 828                 iscsi_free_session(session);
 829                 return NULL;
 830         }
 831         return session;
 832 }
 833 EXPORT_SYMBOL_GPL(iscsi_create_session);
 834
 835 static void iscsi_conn_release(struct device *dev)
 836 {
 837         struct iscsi_cls_conn *conn = iscsi_dev_to_conn(dev);
 838         struct device *parent = conn->dev.parent;
 839
 840         ISCSI_DBG_TRANS_CONN(conn, "Releasing conn\n");
 841         kfree(conn);
 842         put_device(parent);
 843 }
 844
 845 static int iscsi_is_conn_dev(const struct device *dev)
 846 {
 847         return dev->release == iscsi_conn_release;
 848 }
 849
 850 static int iscsi_iter_destroy_conn_fn(struct device *dev, void *data)
 851 {
 852         if (!iscsi_is_conn_dev(dev))
 853                 return 0;
 854         return iscsi_destroy_conn(iscsi_dev_to_conn(dev));
 855 }
 856
 857 void iscsi_remove_session(struct iscsi_cls_session *session)
 858 {
 859         struct Scsi_Host *shost = iscsi_session_to_shost(session);
 860         unsigned long flags;
 861         int err;
 862
 863         ISCSI_DBG_TRANS_SESSION(session, "Removing session\n");
 864
 865         spin_lock_irqsave(&sesslock, flags);
 866         list_del(&session->sess_list);
 867         spin_unlock_irqrestore(&sesslock, flags);
 868
 869         /* make sure there are no blocks/unblocks queued */
 870         flush_workqueue(iscsi_eh_timer_workq);
 871         /* make sure the timedout callout is not running */
 872         if (!cancel_delayed_work(&session->recovery_work))
 873                 flush_workqueue(iscsi_eh_timer_workq);
 874         /*
 875          * If we are blocked let commands flow again. The lld or iscsi
 876          * layer should set up the queuecommand to fail commands.
 877          * We assume that LLD will not be calling block/unblock while
 878          * removing the session.
 879          */
 880         spin_lock_irqsave(&session->lock, flags);
 881         session->state = ISCSI_SESSION_FREE;
 882         spin_unlock_irqrestore(&session->lock, flags);
 883
 884         scsi_target_unblock(&session->dev);
 885         /* flush running scans then delete devices */
 886         scsi_flush_work(shost);
 887         __iscsi_unbind_session(&session->unbind_work);
 888
 889         /* hw iscsi may not have removed all connections from session */
 890         err = device_for_each_child(&session->dev, NULL,
 891                                     iscsi_iter_destroy_conn_fn);
 892         if (err)
 893                 iscsi_cls_session_printk(KERN_ERR, session,
 894                                          "Could not delete all connections "
 895                                          "for session. Error %d.\n", err);
 896
 897         transport_unregister_device(&session->dev);
 898
 899         ISCSI_DBG_TRANS_SESSION(session, "Completing session removal\n");
 900         device_del(&session->dev);
 901 }
 902 EXPORT_SYMBOL_GPL(iscsi_remove_session);
 903
 904 void iscsi_free_session(struct iscsi_cls_session *session)
 905 {
 906         ISCSI_DBG_TRANS_SESSION(session, "Freeing session\n");
 907         iscsi_session_event(session, ISCSI_KEVENT_DESTROY_SESSION);
 908         put_device(&session->dev);
 909 }
 910 EXPORT_SYMBOL_GPL(iscsi_free_session);
 911
 912 /**
 913  * iscsi_destroy_session - destroy iscsi session
 914  * @session: iscsi_session
 915  *
 916  * Can be called by a LLD or iscsi_transport. There must not be
 917  * any running connections.
 918  */
 919 int iscsi_destroy_session(struct iscsi_cls_session *session)
 920 {
 921         iscsi_remove_session(session);
 922         ISCSI_DBG_TRANS_SESSION(session, "Completing session destruction\n");
 923         iscsi_free_session(session);
 924         return 0;
 925 }
 926 EXPORT_SYMBOL_GPL(iscsi_destroy_session);
 927
 928 /**
 929  * iscsi_create_conn - create iscsi class connection
 930  * @session: iscsi cls session
 931  * @dd_size: private driver data size
 932  * @cid: connection id
 933  *
 934  * This can be called from a LLD or iscsi_transport. The connection
 935  * is child of the session so cid must be unique for all connections
 936  * on the session.
 937  *
 938  * Since we do not support MCS, cid will normally be zero. In some cases
 939  * for software iscsi we could be trying to preallocate a connection struct
 940  * in which case there could be two connection structs and cid would be
 941  * non-zero.
 942  */
 943 struct iscsi_cls_conn *
 944 iscsi_create_conn(struct iscsi_cls_session *session, int dd_size, uint32_t cid)
 945 {
 946         struct iscsi_transport *transport = session->transport;
 947         struct iscsi_cls_conn *conn;
 948         unsigned long flags;
 949         int err;
 950
 951         conn = kzalloc(sizeof(*conn) + dd_size, GFP_KERNEL);
 952         if (!conn)
 953                 return NULL;
 954         if (dd_size)
 955                 conn->dd_data = &conn[1];
 956
 957         INIT_LIST_HEAD(&conn->conn_list);
 958         conn->transport = transport;
 959         conn->cid = cid;
 960
 961         /* this is released in the dev's release function */
 962         if (!get_device(&session->dev))
 963                 goto free_conn;
 964
 965         dev_set_name(&conn->dev, "connection%d:%u", session->sid, cid);
 966         conn->dev.parent = &session->dev;
 967         conn->dev.release = iscsi_conn_release;
 968         err = device_register(&conn->dev);
 969         if (err) {
 970                 iscsi_cls_session_printk(KERN_ERR, session, "could not "
 971                                          "register connection's dev\n");
 972                 goto release_parent_ref;
 973         }
 974         transport_register_device(&conn->dev);
 975
 976         spin_lock_irqsave(&connlock, flags);
 977         list_add(&conn->conn_list, &connlist);
 978         conn->active = 1;
 979         spin_unlock_irqrestore(&connlock, flags);
 980
 981         ISCSI_DBG_TRANS_CONN(conn, "Completed conn creation\n");
 982         return conn;
 983
 984 release_parent_ref:
 985         put_device(&session->dev);
 986 free_conn:
 987         kfree(conn);
 988         return NULL;
 989 }
 990
 991 EXPORT_SYMBOL_GPL(iscsi_create_conn);
 992
 993 /**
 994  * iscsi_destroy_conn - destroy iscsi class connection
 995  * @conn: iscsi cls session
 996  *
 997  * This can be called from a LLD or iscsi_transport.
 998  */
 999 int iscsi_destroy_conn(struct iscsi_cls_conn *conn)
1000 {
1001         unsigned long flags;
1002
1003         spin_lock_irqsave(&connlock, flags);
1004         conn->active = 0;
1005         list_del(&conn->conn_list);
1006         spin_unlock_irqrestore(&connlock, flags);
1007
1008         transport_unregister_device(&conn->dev);
1009         ISCSI_DBG_TRANS_CONN(conn, "Completing conn destruction\n");
1010         device_unregister(&conn->dev);
1011         return 0;
1012 }
1013 EXPORT_SYMBOL_GPL(iscsi_destroy_conn);
1014
1015 /*
1016  * iscsi interface functions
1017  */
1018 static struct iscsi_internal *
1019 iscsi_if_transport_lookup(struct iscsi_transport *tt)
1020 {
1021         struct iscsi_internal *priv;
1022         unsigned long flags;
1023
1024         spin_lock_irqsave(&iscsi_transport_lock, flags);
1025         list_for_each_entry(priv, &iscsi_transports, list) {
1026                 if (tt == priv->iscsi_transport) {
1027                         spin_unlock_irqrestore(&iscsi_transport_lock, flags);
1028                         return priv;
1029                 }
1030         }
1031         spin_unlock_irqrestore(&iscsi_transport_lock, flags);
1032         return NULL;
1033 }
1034
1035 static int
1036 iscsi_multicast_skb(struct sk_buff *skb, uint32_t group, gfp_t gfp)
1037 {
1038         return nlmsg_multicast(nls, skb, 0, group, gfp);
1039 }
1040
1041 int iscsi_recv_pdu(struct iscsi_cls_conn *conn, struct iscsi_hdr *hdr,
1042                    char *data, uint32_t data_size)
1043 {
1044         struct nlmsghdr *nlh;
1045         struct sk_buff *skb;
1046         struct iscsi_uevent *ev;
1047         char *pdu;
1048         struct iscsi_internal *priv;
1049         int len = NLMSG_SPACE(sizeof(*ev) + sizeof(struct iscsi_hdr) +
1050                               data_size);
1051
1052         priv = iscsi_if_transport_lookup(conn->transport);
1053         if (!priv)
1054                 return -EINVAL;
1055
1056         skb = alloc_skb(len, GFP_ATOMIC);
1057         if (!skb) {
1058                 iscsi_conn_error_event(conn, ISCSI_ERR_CONN_FAILED);
1059                 iscsi_cls_conn_printk(KERN_ERR, conn, "can not deliver "
1060                                       "control PDU: OOM\n");
1061                 return -ENOMEM;
1062         }
1063
1064         nlh = __nlmsg_put(skb, 0, 0, 0, (len - sizeof(*nlh)), 0);
1065         ev = NLMSG_DATA(nlh);
1066         memset(ev, 0, sizeof(*ev));
1067         ev->transport_handle = iscsi_handle(conn->transport);
1068         ev->type = ISCSI_KEVENT_RECV_PDU;
1069         ev->r.recv_req.cid = conn->cid;
1070         ev->r.recv_req.sid = iscsi_conn_get_sid(conn);
1071         pdu = (char*)ev + sizeof(*ev);
1072         memcpy(pdu, hdr, sizeof(struct iscsi_hdr));
1073         memcpy(pdu + sizeof(struct iscsi_hdr), data, data_size);
1074
1075         return iscsi_multicast_skb(skb, ISCSI_NL_GRP_ISCSID, GFP_ATOMIC);
1076 }
1077 EXPORT_SYMBOL_GPL(iscsi_recv_pdu);
1078
1079 int iscsi_offload_mesg(struct Scsi_Host *shost,
1080                        struct iscsi_transport *transport, uint32_t type,
1081                        char *data, uint16_t data_size)
1082 {
1083         struct nlmsghdr *nlh;
1084         struct sk_buff *skb;
1085         struct iscsi_uevent *ev;
1086         int len = NLMSG_SPACE(sizeof(*ev) + data_size);
1087
1088         skb = alloc_skb(len, GFP_ATOMIC);
1089         if (!skb) {
1090                 printk(KERN_ERR "can not deliver iscsi offload message:OOM\n");
1091                 return -ENOMEM;
1092         }
1093
1094         nlh = __nlmsg_put(skb, 0, 0, 0, (len - sizeof(*nlh)), 0);
1095         ev = NLMSG_DATA(nlh);
1096         memset(ev, 0, sizeof(*ev));
1097         ev->type = type;
1098         ev->transport_handle = iscsi_handle(transport);
1099         switch (type) {
1100         case ISCSI_KEVENT_PATH_REQ:
1101                 ev->r.req_path.host_no = shost->host_no;
1102                 break;
1103         case ISCSI_KEVENT_IF_DOWN:
1104                 ev->r.notify_if_down.host_no = shost->host_no;
1105                 break;
1106         }
1107
1108         memcpy((char *)ev + sizeof(*ev), data, data_size);
1109
1110         return iscsi_multicast_skb(skb, ISCSI_NL_GRP_UIP, GFP_ATOMIC);
1111 }
1112 EXPORT_SYMBOL_GPL(iscsi_offload_mesg);
1113
1114 void iscsi_conn_error_event(struct iscsi_cls_conn *conn, enum iscsi_err error)
1115 {
1116         struct nlmsghdr *nlh;
1117         struct sk_buff  *skb;
1118         struct iscsi_uevent *ev;
1119         struct iscsi_internal *priv;
1120         int len = NLMSG_SPACE(sizeof(*ev));
1121
1122         priv = iscsi_if_transport_lookup(conn->transport);
1123         if (!priv)
1124                 return;
1125
1126         skb = alloc_skb(len, GFP_ATOMIC);
1127         if (!skb) {
1128                 iscsi_cls_conn_printk(KERN_ERR, conn, "gracefully ignored "
1129                                       "conn error (%d)\n", error);
1130                 return;
1131         }
1132
1133         nlh = __nlmsg_put(skb, 0, 0, 0, (len - sizeof(*nlh)), 0);
1134         ev = NLMSG_DATA(nlh);
1135         ev->transport_handle = iscsi_handle(conn->transport);
1136         ev->type = ISCSI_KEVENT_CONN_ERROR;
1137         ev->r.connerror.error = error;
1138         ev->r.connerror.cid = conn->cid;
1139         ev->r.connerror.sid = iscsi_conn_get_sid(conn);
1140
1141         iscsi_multicast_skb(skb, ISCSI_NL_GRP_ISCSID, GFP_ATOMIC);
1142
1143         iscsi_cls_conn_printk(KERN_INFO, conn, "detected conn error (%d)\n",
1144                               error);
1145 }
1146 EXPORT_SYMBOL_GPL(iscsi_conn_error_event);
1147
1148 static int
1149 iscsi_if_send_reply(uint32_t group, int seq, int type, int done, int multi,
1150                     void *payload, int size)
1151 {
1152         struct sk_buff  *skb;
1153         struct nlmsghdr *nlh;
1154         int len = NLMSG_SPACE(size);
1155         int flags = multi ? NLM_F_MULTI : 0;
1156         int t = done ? NLMSG_DONE : type;
1157
1158         skb = alloc_skb(len, GFP_ATOMIC);
1159         if (!skb) {
1160                 printk(KERN_ERR "Could not allocate skb to send reply.\n");
1161                 return -ENOMEM;
1162         }
1163
1164         nlh = __nlmsg_put(skb, 0, 0, t, (len - sizeof(*nlh)), 0);
1165         nlh->nlmsg_flags = flags;
1166         memcpy(NLMSG_DATA(nlh), payload, size);
1167         return iscsi_multicast_skb(skb, group, GFP_ATOMIC);
1168 }
1169
1170 static int
1171 iscsi_if_get_stats(struct iscsi_transport *transport, struct nlmsghdr *nlh)
1172 {
1173         struct iscsi_uevent *ev = NLMSG_DATA(nlh);
1174         struct iscsi_stats *stats;
1175         struct sk_buff *skbstat;
1176         struct iscsi_cls_conn *conn;
1177         struct nlmsghdr *nlhstat;
1178         struct iscsi_uevent *evstat;
1179         struct iscsi_internal *priv;
1180         int len = NLMSG_SPACE(sizeof(*ev) +
1181                               sizeof(struct iscsi_stats) +
1182                               sizeof(struct iscsi_stats_custom) *
1183                               ISCSI_STATS_CUSTOM_MAX);
1184         int err = 0;
1185
1186         priv = iscsi_if_transport_lookup(transport);
1187         if (!priv)
1188                 return -EINVAL;
1189
1190         conn = iscsi_conn_lookup(ev->u.get_stats.sid, ev->u.get_stats.cid);
1191         if (!conn)
1192                 return -EEXIST;
1193
1194         do {
1195                 int actual_size;
1196
1197                 skbstat = alloc_skb(len, GFP_ATOMIC);
1198                 if (!skbstat) {
1199                         iscsi_cls_conn_printk(KERN_ERR, conn, "can not "
1200                                               "deliver stats: OOM\n");
1201                         return -ENOMEM;
1202                 }
1203
1204                 nlhstat = __nlmsg_put(skbstat, 0, 0, 0,
1205                                       (len - sizeof(*nlhstat)), 0);
1206                 evstat = NLMSG_DATA(nlhstat);
1207                 memset(evstat, 0, sizeof(*evstat));
1208                 evstat->transport_handle = iscsi_handle(conn->transport);
1209                 evstat->type = nlh->nlmsg_type;
1210                 evstat->u.get_stats.cid =
1211                         ev->u.get_stats.cid;
1212                 evstat->u.get_stats.sid =
1213                         ev->u.get_stats.sid;
1214                 stats = (struct iscsi_stats *)
1215                         ((char*)evstat + sizeof(*evstat));
1216                 memset(stats, 0, sizeof(*stats));
1217
1218                 transport->get_stats(conn, stats);
1219                 actual_size = NLMSG_SPACE(sizeof(struct iscsi_uevent) +
1220                                           sizeof(struct iscsi_stats) +
1221                                           sizeof(struct iscsi_stats_custom) *
1222                                           stats->custom_length);
1223                 actual_size -= sizeof(*nlhstat);
1224                 actual_size = NLMSG_LENGTH(actual_size);
1225                 skb_trim(skbstat, NLMSG_ALIGN(actual_size));
1226                 nlhstat->nlmsg_len = actual_size;
1227
1228                 err = iscsi_multicast_skb(skbstat, ISCSI_NL_GRP_ISCSID,
1229                                           GFP_ATOMIC);
1230         } while (err < 0 && err != -ECONNREFUSED);
1231
1232         return err;
1233 }
1234
1235 /**
1236  * iscsi_session_event - send session destr. completion event
1237  * @session: iscsi class session
1238  * @event: type of event
1239  */
1240 int iscsi_session_event(struct iscsi_cls_session *session,
1241                         enum iscsi_uevent_e event)
1242 {
1243         struct iscsi_internal *priv;
1244         struct Scsi_Host *shost;
1245         struct iscsi_uevent *ev;
1246         struct sk_buff  *skb;
1247         struct nlmsghdr *nlh;
1248         int rc, len = NLMSG_SPACE(sizeof(*ev));
1249
1250         priv = iscsi_if_transport_lookup(session->transport);
1251         if (!priv)
1252                 return -EINVAL;
1253         shost = iscsi_session_to_shost(session);
1254
1255         skb = alloc_skb(len, GFP_KERNEL);
1256         if (!skb) {
1257                 iscsi_cls_session_printk(KERN_ERR, session,
1258                                          "Cannot notify userspace of session "
1259                                          "event %u\n", event);
1260                 return -ENOMEM;
1261         }
1262
1263         nlh = __nlmsg_put(skb, 0, 0, 0, (len - sizeof(*nlh)), 0);
1264         ev = NLMSG_DATA(nlh);
1265         ev->transport_handle = iscsi_handle(session->transport);
1266
1267         ev->type = event;
1268         switch (event) {
1269         case ISCSI_KEVENT_DESTROY_SESSION:
1270                 ev->r.d_session.host_no = shost->host_no;
1271                 ev->r.d_session.sid = session->sid;
1272                 break;
1273         case ISCSI_KEVENT_CREATE_SESSION:
1274                 ev->r.c_session_ret.host_no = shost->host_no;
1275                 ev->r.c_session_ret.sid = session->sid;
1276                 break;
1277         case ISCSI_KEVENT_UNBIND_SESSION:
1278                 ev->r.unbind_session.host_no = shost->host_no;
1279                 ev->r.unbind_session.sid = session->sid;
1280                 break;
1281         default:
1282                 iscsi_cls_session_printk(KERN_ERR, session, "Invalid event "
1283                                          "%u.\n", event);
1284                 kfree_skb(skb);
1285                 return -EINVAL;
1286         }
1287
1288         /*
1289          * this will occur if the daemon is not up, so we just warn
1290          * the user and when the daemon is restarted it will handle it
1291          */
1292         rc = iscsi_multicast_skb(skb, ISCSI_NL_GRP_ISCSID, GFP_KERNEL);
1293         if (rc == -ESRCH)
1294                 iscsi_cls_session_printk(KERN_ERR, session,
1295                                          "Cannot notify userspace of session "
1296                                          "event %u. Check iscsi daemon\n",
1297                                          event);
1298
1299         ISCSI_DBG_TRANS_SESSION(session, "Completed handling event %d rc %d\n",
1300                                 event, rc);
1301         return rc;
1302 }
1303 EXPORT_SYMBOL_GPL(iscsi_session_event);
1304
1305 static int
1306 iscsi_if_create_session(struct iscsi_internal *priv, struct iscsi_endpoint *ep,
1307                         struct iscsi_uevent *ev, uint32_t initial_cmdsn,
1308                         uint16_t cmds_max, uint16_t queue_depth)
1309 {
1310         struct iscsi_transport *transport = priv->iscsi_transport;
1311         struct iscsi_cls_session *session;
1312         struct Scsi_Host *shost;
1313
1314         session = transport->create_session(ep, cmds_max, queue_depth,
1315                                             initial_cmdsn);
1316         if (!session)
1317                 return -ENOMEM;
1318
1319         shost = iscsi_session_to_shost(session);
1320         ev->r.c_session_ret.host_no = shost->host_no;
1321         ev->r.c_session_ret.sid = session->sid;
1322         ISCSI_DBG_TRANS_SESSION(session,
1323                                 "Completed creating transport session\n");
1324         return 0;
1325 }
1326
1327 static int
1328 iscsi_if_create_conn(struct iscsi_transport *transport, struct iscsi_uevent *ev)
1329 {
1330         struct iscsi_cls_conn *conn;
1331         struct iscsi_cls_session *session;
1332
1333         session = iscsi_session_lookup(ev->u.c_conn.sid);
1334         if (!session) {
1335                 printk(KERN_ERR "iscsi: invalid session %d.\n",
1336                        ev->u.c_conn.sid);
1337                 return -EINVAL;
1338         }
1339
1340         conn = transport->create_conn(session, ev->u.c_conn.cid);
1341         if (!conn) {
1342                 iscsi_cls_session_printk(KERN_ERR, session,
1343                                          "couldn't create a new connection.");
1344                 return -ENOMEM;
1345         }
1346
1347         ev->r.c_conn_ret.sid = session->sid;
1348         ev->r.c_conn_ret.cid = conn->cid;
1349
1350         ISCSI_DBG_TRANS_CONN(conn, "Completed creating transport conn\n");
1351         return 0;
1352 }
1353
1354 static int
1355 iscsi_if_destroy_conn(struct iscsi_transport *transport, struct iscsi_uevent *ev)
1356 {
1357         struct iscsi_cls_conn *conn;
1358
1359         conn = iscsi_conn_lookup(ev->u.d_conn.sid, ev->u.d_conn.cid);
1360         if (!conn)
1361                 return -EINVAL;
1362
1363         ISCSI_DBG_TRANS_CONN(conn, "Destroying transport conn\n");
1364         if (transport->destroy_conn)
1365                 transport->destroy_conn(conn);
1366
1367         return 0;
1368 }
1369
1370 static int
1371 iscsi_set_param(struct iscsi_transport *transport, struct iscsi_uevent *ev)
1372 {
1373         char *data = (char*)ev + sizeof(*ev);
1374         struct iscsi_cls_conn *conn;
1375         struct iscsi_cls_session *session;
1376         int err = 0, value = 0;
1377
1378         session = iscsi_session_lookup(ev->u.set_param.sid);
1379         conn = iscsi_conn_lookup(ev->u.set_param.sid, ev->u.set_param.cid);
1380         if (!conn || !session)
1381                 return -EINVAL;
1382
1383         switch (ev->u.set_param.param) {
1384         case ISCSI_PARAM_SESS_RECOVERY_TMO:
1385                 sscanf(data, "%d", &value);
1386                 session->recovery_tmo = value;
1387                 break;
1388         default:
1389                 err = transport->set_param(conn, ev->u.set_param.param,
1390                                            data, ev->u.set_param.len);
1391         }
1392
1393         return err;
1394 }
1395
1396 static int iscsi_if_ep_connect(struct iscsi_transport *transport,
1397                                struct iscsi_uevent *ev, int msg_type)
1398 {
1399         struct iscsi_endpoint *ep;
1400         struct sockaddr *dst_addr;
1401         struct Scsi_Host *shost = NULL;
1402         int non_blocking, err = 0;
1403
1404         if (!transport->ep_connect)
1405                 return -EINVAL;
1406
1407         if (msg_type == ISCSI_UEVENT_TRANSPORT_EP_CONNECT_THROUGH_HOST) {
1408                 shost = scsi_host_lookup(ev->u.ep_connect_through_host.host_no);
1409                 if (!shost) {
1410                         printk(KERN_ERR "ep connect failed. Could not find "
1411                                "host no %u\n",
1412                                ev->u.ep_connect_through_host.host_no);
1413                         return -ENODEV;
1414                 }
1415                 non_blocking = ev->u.ep_connect_through_host.non_blocking;
1416         } else
1417                 non_blocking = ev->u.ep_connect.non_blocking;
1418
1419         dst_addr = (struct sockaddr *)((char*)ev + sizeof(*ev));
1420         ep = transport->ep_connect(shost, dst_addr, non_blocking);
1421         if (IS_ERR(ep)) {
1422                 err = PTR_ERR(ep);
1423                 goto release_host;
1424         }
1425
1426         ev->r.ep_connect_ret.handle = ep->id;
1427 release_host:
1428         if (shost)
1429                 scsi_host_put(shost);
1430         return err;
1431 }
1432
1433 static int
1434 iscsi_if_transport_ep(struct iscsi_transport *transport,
1435                       struct iscsi_uevent *ev, int msg_type)
1436 {
1437         struct iscsi_endpoint *ep;
1438         int rc = 0;
1439
1440         switch (msg_type) {
1441         case ISCSI_UEVENT_TRANSPORT_EP_CONNECT_THROUGH_HOST:
1442         case ISCSI_UEVENT_TRANSPORT_EP_CONNECT:
1443                 rc = iscsi_if_ep_connect(transport, ev, msg_type);
1444                 break;
1445         case ISCSI_UEVENT_TRANSPORT_EP_POLL:
1446                 if (!transport->ep_poll)
1447                         return -EINVAL;
1448
1449                 ep = iscsi_lookup_endpoint(ev->u.ep_poll.ep_handle);
1450                 if (!ep)
1451                         return -EINVAL;
1452
1453                 ev->r.retcode = transport->ep_poll(ep,
1454                                                    ev->u.ep_poll.timeout_ms);
1455                 break;
1456         case ISCSI_UEVENT_TRANSPORT_EP_DISCONNECT:
1457                 if (!transport->ep_disconnect)
1458                         return -EINVAL;
1459
1460                 ep = iscsi_lookup_endpoint(ev->u.ep_disconnect.ep_handle);
1461                 if (!ep)
1462                         return -EINVAL;
1463
1464                 transport->ep_disconnect(ep);
1465                 break;
1466         }
1467         return rc;
1468 }
1469
1470 static int
1471 iscsi_tgt_dscvr(struct iscsi_transport *transport,
1472                 struct iscsi_uevent *ev)
1473 {
1474         struct Scsi_Host *shost;
1475         struct sockaddr *dst_addr;
1476         int err;
1477
1478         if (!transport->tgt_dscvr)
1479                 return -EINVAL;
1480
1481         shost = scsi_host_lookup(ev->u.tgt_dscvr.host_no);
1482         if (!shost) {
1483                 printk(KERN_ERR "target discovery could not find host no %u\n",
1484                        ev->u.tgt_dscvr.host_no);
1485                 return -ENODEV;
1486         }
1487
1488
1489         dst_addr = (struct sockaddr *)((char*)ev + sizeof(*ev));
1490         err = transport->tgt_dscvr(shost, ev->u.tgt_dscvr.type,
1491                                    ev->u.tgt_dscvr.enable, dst_addr);
1492         scsi_host_put(shost);
1493         return err;
1494 }
1495
1496 static int
1497 iscsi_set_host_param(struct iscsi_transport *transport,
1498                      struct iscsi_uevent *ev)
1499 {
1500         char *data = (char*)ev + sizeof(*ev);
1501         struct Scsi_Host *shost;
1502         int err;
1503
1504         if (!transport->set_host_param)
1505                 return -ENOSYS;
1506
1507         shost = scsi_host_lookup(ev->u.set_host_param.host_no);
1508         if (!shost) {
1509                 printk(KERN_ERR "set_host_param could not find host no %u\n",
1510                        ev->u.set_host_param.host_no);
1511                 return -ENODEV;
1512         }
1513
1514         err = transport->set_host_param(shost, ev->u.set_host_param.param,
1515                                         data, ev->u.set_host_param.len);
1516         scsi_host_put(shost);
1517         return err;
1518 }
1519
1520 static int
1521 iscsi_set_path(struct iscsi_transport *transport, struct iscsi_uevent *ev)
1522 {
1523         struct Scsi_Host *shost;
1524         struct iscsi_path *params;
1525         int err;
1526
1527         if (!transport->set_path)
1528                 return -ENOSYS;
1529
1530         shost = scsi_host_lookup(ev->u.set_path.host_no);
1531         if (!shost) {
1532                 printk(KERN_ERR "set path could not find host no %u\n",
1533                        ev->u.set_path.host_no);
1534                 return -ENODEV;
1535         }
1536
1537         params = (struct iscsi_path *)((char *)ev + sizeof(*ev));
1538         err = transport->set_path(shost, params);
1539
1540         scsi_host_put(shost);
1541         return err;
1542 }
1543
1544 static int
1545 iscsi_if_recv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, uint32_t *group)
1546 {
1547         int err = 0;
1548         struct iscsi_uevent *ev = NLMSG_DATA(nlh);
1549         struct iscsi_transport *transport = NULL;
1550         struct iscsi_internal *priv;
1551         struct iscsi_cls_session *session;
1552         struct iscsi_cls_conn *conn;
1553         struct iscsi_endpoint *ep = NULL;
1554
1555         if (nlh->nlmsg_type == ISCSI_UEVENT_PATH_UPDATE)
1556                 *group = ISCSI_NL_GRP_UIP;
1557         else
1558                 *group = ISCSI_NL_GRP_ISCSID;
1559
1560         priv = iscsi_if_transport_lookup(iscsi_ptr(ev->transport_handle));
1561         if (!priv)
1562                 return -EINVAL;
1563         transport = priv->iscsi_transport;
1564
1565         if (!try_module_get(transport->owner))
1566                 return -EINVAL;
1567
1568         switch (nlh->nlmsg_type) {
1569         case ISCSI_UEVENT_CREATE_SESSION:
1570                 err = iscsi_if_create_session(priv, ep, ev,
1571                                               ev->u.c_session.initial_cmdsn,
1572                                               ev->u.c_session.cmds_max,
1573                                               ev->u.c_session.queue_depth);
1574                 break;
1575         case ISCSI_UEVENT_CREATE_BOUND_SESSION:
1576                 ep = iscsi_lookup_endpoint(ev->u.c_bound_session.ep_handle);
1577                 if (!ep) {
1578                         err = -EINVAL;
1579                         break;
1580                 }
1581
1582                 err = iscsi_if_create_session(priv, ep, ev,
1583                                         ev->u.c_bound_session.initial_cmdsn,
1584                                         ev->u.c_bound_session.cmds_max,
1585                                         ev->u.c_bound_session.queue_depth);
1586                 break;
1587         case ISCSI_UEVENT_DESTROY_SESSION:
1588                 session = iscsi_session_lookup(ev->u.d_session.sid);
1589                 if (session)
1590                         transport->destroy_session(session);
1591                 else
1592                         err = -EINVAL;
1593                 break;
1594         case ISCSI_UEVENT_UNBIND_SESSION:
1595                 session = iscsi_session_lookup(ev->u.d_session.sid);
1596                 if (session)
1597                         scsi_queue_work(iscsi_session_to_shost(session),
1598                                         &session->unbind_work);
1599                 else
1600                         err = -EINVAL;
1601                 break;
1602         case ISCSI_UEVENT_CREATE_CONN:
1603                 err = iscsi_if_create_conn(transport, ev);
1604                 break;
1605         case ISCSI_UEVENT_DESTROY_CONN:
1606                 err = iscsi_if_destroy_conn(transport, ev);
1607                 break;
1608         case ISCSI_UEVENT_BIND_CONN:
1609                 session = iscsi_session_lookup(ev->u.b_conn.sid);
1610                 conn = iscsi_conn_lookup(ev->u.b_conn.sid, ev->u.b_conn.cid);
1611
1612                 if (session && conn)
1613                         ev->r.retcode = transport->bind_conn(session, conn,
1614                                         ev->u.b_conn.transport_eph,
1615                                         ev->u.b_conn.is_leading);
1616                 else
1617                         err = -EINVAL;
1618                 break;
1619         case ISCSI_UEVENT_SET_PARAM:
1620                 err = iscsi_set_param(transport, ev);
1621                 break;
1622         case ISCSI_UEVENT_START_CONN:
1623                 conn = iscsi_conn_lookup(ev->u.start_conn.sid, ev->u.start_conn.cid);
1624                 if (conn)
1625                         ev->r.retcode = transport->start_conn(conn);
1626                 else
1627                         err = -EINVAL;
1628                 break;
1629         case ISCSI_UEVENT_STOP_CONN:
1630                 conn = iscsi_conn_lookup(ev->u.stop_conn.sid, ev->u.stop_conn.cid);
1631                 if (conn)
1632                         transport->stop_conn(conn, ev->u.stop_conn.flag);
1633                 else
1634                         err = -EINVAL;
1635                 break;
1636         case ISCSI_UEVENT_SEND_PDU:
1637                 conn = iscsi_conn_lookup(ev->u.send_pdu.sid, ev->u.send_pdu.cid);
1638                 if (conn)
1639                         ev->r.retcode = transport->send_pdu(conn,
1640                                 (struct iscsi_hdr*)((char*)ev + sizeof(*ev)),
1641                                 (char*)ev + sizeof(*ev) + ev->u.send_pdu.hdr_size,
1642                                 ev->u.send_pdu.data_size);
1643                 else
1644                         err = -EINVAL;
1645                 break;
1646         case ISCSI_UEVENT_GET_STATS:
1647                 err = iscsi_if_get_stats(transport, nlh);
1648                 break;
1649         case ISCSI_UEVENT_TRANSPORT_EP_CONNECT:
1650         case ISCSI_UEVENT_TRANSPORT_EP_POLL:
1651         case ISCSI_UEVENT_TRANSPORT_EP_DISCONNECT:
1652         case ISCSI_UEVENT_TRANSPORT_EP_CONNECT_THROUGH_HOST:
1653                 err = iscsi_if_transport_ep(transport, ev, nlh->nlmsg_type);
1654                 break;
1655         case ISCSI_UEVENT_TGT_DSCVR:
1656                 err = iscsi_tgt_dscvr(transport, ev);
1657                 break;
1658         case ISCSI_UEVENT_SET_HOST_PARAM:
1659                 err = iscsi_set_host_param(transport, ev);
1660                 break;
1661         case ISCSI_UEVENT_PATH_UPDATE:
1662                 err = iscsi_set_path(transport, ev);
1663                 break;
1664         default:
1665                 err = -ENOSYS;
1666                 break;
1667         }
1668
1669         module_put(transport->owner);
1670         return err;
1671 }
1672
1673 /*
1674  * Get message from skb.  Each message is processed by iscsi_if_recv_msg.
1675  * Malformed skbs with wrong lengths or invalid creds are not processed.
1676  */
1677 static void
1678 iscsi_if_rx(struct sk_buff *skb)
1679 {
1680         mutex_lock(&rx_queue_mutex);
1681         while (skb->len >= NLMSG_SPACE(0)) {
1682                 int err;
1683                 uint32_t rlen;
1684                 struct nlmsghdr *nlh;
1685                 struct iscsi_uevent *ev;
1686                 uint32_t group;
1687
1688                 nlh = nlmsg_hdr(skb);
1689                 if (nlh->nlmsg_len < sizeof(*nlh) ||
1690                     skb->len < nlh->nlmsg_len) {
1691                         break;
1692                 }
1693
1694                 ev = NLMSG_DATA(nlh);
1695                 rlen = NLMSG_ALIGN(nlh->nlmsg_len);
1696                 if (rlen > skb->len)
1697                         rlen = skb->len;
1698
1699                 err = iscsi_if_recv_msg(skb, nlh, &group);
1700                 if (err) {
1701                         ev->type = ISCSI_KEVENT_IF_ERROR;
1702                         ev->iferror = err;
1703                 }
1704                 do {
1705                         /*
1706                          * special case for GET_STATS:
1707                          * on success - sending reply and stats from
1708                          * inside of if_recv_msg(),
1709                          * on error - fall through.
1710                          */
1711                         if (ev->type == ISCSI_UEVENT_GET_STATS && !err)
1712                                 break;
1713                         err = iscsi_if_send_reply(group, nlh->nlmsg_seq,
1714                                 nlh->nlmsg_type, 0, 0, ev, sizeof(*ev));
1715                 } while (err < 0 && err != -ECONNREFUSED);
1716                 skb_pull(skb, rlen);
1717         }
1718         mutex_unlock(&rx_queue_mutex);
1719 }
1720
1721 #define ISCSI_CLASS_ATTR(_prefix,_name,_mode,_show,_store)              \
1722 struct device_attribute dev_attr_##_prefix##_##_name =  \
1723         __ATTR(_name,_mode,_show,_store)
1724
1725 /*
1726  * iSCSI connection attrs
1727  */
1728 #define iscsi_conn_attr_show(param)                                     \
1729 static ssize_t                                                          \
1730 show_conn_param_##param(struct device *dev,                             \
1731                         struct device_attribute *attr, char *buf)       \
1732 {                                                                       \
1733         struct iscsi_cls_conn *conn = iscsi_dev_to_conn(dev->parent);   \
1734         struct iscsi_transport *t = conn->transport;                    \
1735         return t->get_conn_param(conn, param, buf);                     \
1736 }
1737
1738 #define iscsi_conn_attr(field, param)                                   \
1739         iscsi_conn_attr_show(param)                                     \
1740 static ISCSI_CLASS_ATTR(conn, field, S_IRUGO, show_conn_param_##param,  \
1741                         NULL);
1742
1743 iscsi_conn_attr(max_recv_dlength, ISCSI_PARAM_MAX_RECV_DLENGTH);
1744 iscsi_conn_attr(max_xmit_dlength, ISCSI_PARAM_MAX_XMIT_DLENGTH);
1745 iscsi_conn_attr(header_digest, ISCSI_PARAM_HDRDGST_EN);
1746 iscsi_conn_attr(data_digest, ISCSI_PARAM_DATADGST_EN);
1747 iscsi_conn_attr(ifmarker, ISCSI_PARAM_IFMARKER_EN);
1748 iscsi_conn_attr(ofmarker, ISCSI_PARAM_OFMARKER_EN);
1749 iscsi_conn_attr(persistent_port, ISCSI_PARAM_PERSISTENT_PORT);
1750 iscsi_conn_attr(port, ISCSI_PARAM_CONN_PORT);
1751 iscsi_conn_attr(exp_statsn, ISCSI_PARAM_EXP_STATSN);
1752 iscsi_conn_attr(persistent_address, ISCSI_PARAM_PERSISTENT_ADDRESS);
1753 iscsi_conn_attr(address, ISCSI_PARAM_CONN_ADDRESS);
1754 iscsi_conn_attr(ping_tmo, ISCSI_PARAM_PING_TMO);
1755 iscsi_conn_attr(recv_tmo, ISCSI_PARAM_RECV_TMO);
1756
1757 /*
1758  * iSCSI session attrs
1759  */
1760 #define iscsi_session_attr_show(param, perm)                            \
1761 static ssize_t                                                          \
1762 show_session_param_##param(struct device *dev,                          \
1763                            struct device_attribute *attr, char *buf)    \
1764 {                                                                       \
1765         struct iscsi_cls_session *session =                             \
1766                 iscsi_dev_to_session(dev->parent);                      \
1767         struct iscsi_transport *t = session->transport;                 \
1768                                                                         \
1769         if (perm && !capable(CAP_SYS_ADMIN))                            \
1770                 return -EACCES;                                         \
1771         return t->get_session_param(session, param, buf);               \
1772 }
1773
1774 #define iscsi_session_attr(field, param, perm)                          \
1775         iscsi_session_attr_show(param, perm)                            \
1776 static ISCSI_CLASS_ATTR(sess, field, S_IRUGO, show_session_param_##param, \
1777                         NULL);
1778
1779 iscsi_session_attr(targetname, ISCSI_PARAM_TARGET_NAME, 0);
1780 iscsi_session_attr(initial_r2t, ISCSI_PARAM_INITIAL_R2T_EN, 0);
1781 iscsi_session_attr(max_outstanding_r2t, ISCSI_PARAM_MAX_R2T, 0);
1782 iscsi_session_attr(immediate_data, ISCSI_PARAM_IMM_DATA_EN, 0);
1783 iscsi_session_attr(first_burst_len, ISCSI_PARAM_FIRST_BURST, 0);
1784 iscsi_session_attr(max_burst_len, ISCSI_PARAM_MAX_BURST, 0);
1785 iscsi_session_attr(data_pdu_in_order, ISCSI_PARAM_PDU_INORDER_EN, 0);
1786 iscsi_session_attr(data_seq_in_order, ISCSI_PARAM_DATASEQ_INORDER_EN, 0);
1787 iscsi_session_attr(erl, ISCSI_PARAM_ERL, 0);
1788 iscsi_session_attr(tpgt, ISCSI_PARAM_TPGT, 0);
1789 iscsi_session_attr(username, ISCSI_PARAM_USERNAME, 1);
1790 iscsi_session_attr(username_in, ISCSI_PARAM_USERNAME_IN, 1);
1791 iscsi_session_attr(password, ISCSI_PARAM_PASSWORD, 1);
1792 iscsi_session_attr(password_in, ISCSI_PARAM_PASSWORD_IN, 1);
1793 iscsi_session_attr(fast_abort, ISCSI_PARAM_FAST_ABORT, 0);
1794 iscsi_session_attr(abort_tmo, ISCSI_PARAM_ABORT_TMO, 0);
1795 iscsi_session_attr(lu_reset_tmo, ISCSI_PARAM_LU_RESET_TMO, 0);
1796 iscsi_session_attr(tgt_reset_tmo, ISCSI_PARAM_TGT_RESET_TMO, 0);
1797 iscsi_session_attr(ifacename, ISCSI_PARAM_IFACE_NAME, 0);
1798 iscsi_session_attr(initiatorname, ISCSI_PARAM_INITIATOR_NAME, 0);
1799 iscsi_session_attr(targetalias, ISCSI_PARAM_TARGET_ALIAS, 0);
1800
1801 static ssize_t
1802 show_priv_session_state(struct device *dev, struct device_attribute *attr,
1803                         char *buf)
1804 {
1805         struct iscsi_cls_session *session = iscsi_dev_to_session(dev->parent);
1806         return sprintf(buf, "%s\n", iscsi_session_state_name(session->state));
1807 }
1808 static ISCSI_CLASS_ATTR(priv_sess, state, S_IRUGO, show_priv_session_state,
1809                         NULL);
1810
1811 #define iscsi_priv_session_attr_show(field, format)                     \
1812 static ssize_t                                                          \
1813 show_priv_session_##field(struct device *dev,                           \
1814                           struct device_attribute *attr, char *buf)     \
1815 {                                                                       \
1816         struct iscsi_cls_session *session =                             \
1817                         iscsi_dev_to_session(dev->parent);              \
1818         if (session->field == -1)                                       \
1819                 return sprintf(buf, "off\n");                           \
1820         return sprintf(buf, format"\n", session->field);                \
1821 }
1822
1823 #define iscsi_priv_session_attr_store(field)                            \
1824 static ssize_t                                                          \
1825 store_priv_session_##field(struct device *dev,                          \
1826                            struct device_attribute *attr,               \
1827                            const char *buf, size_t count)               \
1828 {                                                                       \
1829         int val;                                                        \
1830         char *cp;                                                       \
1831         struct iscsi_cls_session *session =                             \
1832                 iscsi_dev_to_session(dev->parent);                      \
1833         if ((session->state == ISCSI_SESSION_FREE) ||                   \
1834             (session->state == ISCSI_SESSION_FAILED))                   \
1835                 return -EBUSY;                                          \
1836         if (strncmp(buf, "off", 3) == 0)                                \
1837                 session->field = -1;                                    \
1838         else {                                                          \
1839                 val = simple_strtoul(buf, &cp, 0);                      \
1840                 if (*cp != '\0' && *cp != '\n')                         \
1841                         return -EINVAL;                                 \
1842                 session->field = val;                                   \
1843         }                                                               \
1844         return count;                                                   \
1845 }
1846
1847 #define iscsi_priv_session_rw_attr(field, format)                       \
1848         iscsi_priv_session_attr_show(field, format)                     \
1849         iscsi_priv_session_attr_store(field)                            \
1850 static ISCSI_CLASS_ATTR(priv_sess, field, S_IRUGO | S_IWUGO,            \
1851                         show_priv_session_##field,                      \
1852                         store_priv_session_##field)
1853 iscsi_priv_session_rw_attr(recovery_tmo, "%d");
1854
1855 /*
1856  * iSCSI host attrs
1857  */
1858 #define iscsi_host_attr_show(param)                                     \
1859 static ssize_t                                                          \
1860 show_host_param_##param(struct device *dev,                             \
1861                         struct device_attribute *attr, char *buf)       \
1862 {                                                                       \
1863         struct Scsi_Host *shost = transport_class_to_shost(dev);        \
1864         struct iscsi_internal *priv = to_iscsi_internal(shost->transportt); \
1865         return priv->iscsi_transport->get_host_param(shost, param, buf); \
1866 }
1867
1868 #define iscsi_host_attr(field, param)                                   \
1869         iscsi_host_attr_show(param)                                     \
1870 static ISCSI_CLASS_ATTR(host, field, S_IRUGO, show_host_param_##param,  \
1871                         NULL);
1872
1873 iscsi_host_attr(netdev, ISCSI_HOST_PARAM_NETDEV_NAME);
1874 iscsi_host_attr(hwaddress, ISCSI_HOST_PARAM_HWADDRESS);
1875 iscsi_host_attr(ipaddress, ISCSI_HOST_PARAM_IPADDRESS);
1876 iscsi_host_attr(initiatorname, ISCSI_HOST_PARAM_INITIATOR_NAME);
1877
1878 #define SETUP_PRIV_SESSION_RD_ATTR(field)                               \
1879 do {                                                                    \
1880         priv->session_attrs[count] = &dev_attr_priv_sess_##field; \
1881         count++;                                                        \
1882 } while (0)
1883
1884 #define SETUP_PRIV_SESSION_RW_ATTR(field)                               \
1885 do {                                                                    \
1886         priv->session_attrs[count] = &dev_attr_priv_sess_##field;       \
1887         count++;                                                        \
1888 } while (0)
1889
1890 #define SETUP_SESSION_RD_ATTR(field, param_flag)                        \
1891 do {                                                                    \
1892         if (tt->param_mask & param_flag) {                              \
1893                 priv->session_attrs[count] = &dev_attr_sess_##field; \
1894                 count++;                                                \
1895         }                                                               \
1896 } while (0)
1897
1898 #define SETUP_CONN_RD_ATTR(field, param_flag)                           \
1899 do {                                                                    \
1900         if (tt->param_mask & param_flag) {                              \
1901                 priv->conn_attrs[count] = &dev_attr_conn_##field; \
1902                 count++;                                                \
1903         }                                                               \
1904 } while (0)
1905
1906 #define SETUP_HOST_RD_ATTR(field, param_flag)                           \
1907 do {                                                                    \
1908         if (tt->host_param_mask & param_flag) {                         \
1909                 priv->host_attrs[count] = &dev_attr_host_##field; \
1910                 count++;                                                \
1911         }                                                               \
1912 } while (0)
1913
1914 static int iscsi_session_match(struct attribute_container *cont,
1915                            struct device *dev)
1916 {
1917         struct iscsi_cls_session *session;
1918         struct Scsi_Host *shost;
1919         struct iscsi_internal *priv;
1920
1921         if (!iscsi_is_session_dev(dev))
1922                 return 0;
1923
1924         session = iscsi_dev_to_session(dev);
1925         shost = iscsi_session_to_shost(session);
1926         if (!shost->transportt)
1927                 return 0;
1928
1929         priv = to_iscsi_internal(shost->transportt);
1930         if (priv->session_cont.ac.class != &iscsi_session_class.class)
1931                 return 0;
1932
1933         return &priv->session_cont.ac == cont;
1934 }
1935
1936 static int iscsi_conn_match(struct attribute_container *cont,
1937                            struct device *dev)
1938 {
1939         struct iscsi_cls_session *session;
1940         struct iscsi_cls_conn *conn;
1941         struct Scsi_Host *shost;
1942         struct iscsi_internal *priv;
1943
1944         if (!iscsi_is_conn_dev(dev))
1945                 return 0;
1946
1947         conn = iscsi_dev_to_conn(dev);
1948         session = iscsi_dev_to_session(conn->dev.parent);
1949         shost = iscsi_session_to_shost(session);
1950
1951         if (!shost->transportt)
1952                 return 0;
1953
1954         priv = to_iscsi_internal(shost->transportt);
1955         if (priv->conn_cont.ac.class != &iscsi_connection_class.class)
1956                 return 0;
1957
1958         return &priv->conn_cont.ac == cont;
1959 }
1960
1961 static int iscsi_host_match(struct attribute_container *cont,
1962                             struct device *dev)
1963 {
1964         struct Scsi_Host *shost;
1965         struct iscsi_internal *priv;
1966
1967         if (!scsi_is_host_device(dev))
1968                 return 0;
1969
1970         shost = dev_to_shost(dev);
1971         if (!shost->transportt  ||
1972             shost->transportt->host_attrs.ac.class != &iscsi_host_class.class)
1973                 return 0;
1974
1975         priv = to_iscsi_internal(shost->transportt);
1976         return &priv->t.host_attrs.ac == cont;
1977 }
1978
1979 struct scsi_transport_template *
1980 iscsi_register_transport(struct iscsi_transport *tt)
1981 {
1982         struct iscsi_internal *priv;
1983         unsigned long flags;
1984         int count = 0, err;
1985
1986         BUG_ON(!tt);
1987
1988         priv = iscsi_if_transport_lookup(tt);
1989         if (priv)
1990                 return NULL;
1991
1992         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
1993         if (!priv)
1994                 return NULL;
1995         INIT_LIST_HEAD(&priv->list);
1996         priv->iscsi_transport = tt;
1997         priv->t.user_scan = iscsi_user_scan;
1998         priv->t.create_work_queue = 1;
1999
2000         priv->dev.class = &iscsi_transport_class;
2001         dev_set_name(&priv->dev, "%s", tt->name);
2002         err = device_register(&priv->dev);
2003         if (err)
2004                 goto free_priv;
2005
2006         err = sysfs_create_group(&priv->dev.kobj, &iscsi_transport_group);
2007         if (err)
2008                 goto unregister_dev;
2009
2010         /* host parameters */
2011         priv->t.host_attrs.ac.attrs = &priv->host_attrs[0];
2012         priv->t.host_attrs.ac.class = &iscsi_host_class.class;
2013         priv->t.host_attrs.ac.match = iscsi_host_match;
2014         priv->t.host_size = sizeof(struct iscsi_cls_host);
2015         transport_container_register(&priv->t.host_attrs);
2016
2017         SETUP_HOST_RD_ATTR(netdev, ISCSI_HOST_NETDEV_NAME);
2018         SETUP_HOST_RD_ATTR(ipaddress, ISCSI_HOST_IPADDRESS);
2019         SETUP_HOST_RD_ATTR(hwaddress, ISCSI_HOST_HWADDRESS);
2020         SETUP_HOST_RD_ATTR(initiatorname, ISCSI_HOST_INITIATOR_NAME);
2021         BUG_ON(count > ISCSI_HOST_ATTRS);
2022         priv->host_attrs[count] = NULL;
2023         count = 0;
2024
2025         /* connection parameters */
2026         priv->conn_cont.ac.attrs = &priv->conn_attrs[0];
2027         priv->conn_cont.ac.class = &iscsi_connection_class.class;
2028         priv->conn_cont.ac.match = iscsi_conn_match;
2029         transport_container_register(&priv->conn_cont);
2030
2031         SETUP_CONN_RD_ATTR(max_recv_dlength, ISCSI_MAX_RECV_DLENGTH);
2032         SETUP_CONN_RD_ATTR(max_xmit_dlength, ISCSI_MAX_XMIT_DLENGTH);
2033         SETUP_CONN_RD_ATTR(header_digest, ISCSI_HDRDGST_EN);
2034         SETUP_CONN_RD_ATTR(data_digest, ISCSI_DATADGST_EN);
2035         SETUP_CONN_RD_ATTR(ifmarker, ISCSI_IFMARKER_EN);
2036         SETUP_CONN_RD_ATTR(ofmarker, ISCSI_OFMARKER_EN);
2037         SETUP_CONN_RD_ATTR(address, ISCSI_CONN_ADDRESS);
2038         SETUP_CONN_RD_ATTR(port, ISCSI_CONN_PORT);
2039         SETUP_CONN_RD_ATTR(exp_statsn, ISCSI_EXP_STATSN);
2040         SETUP_CONN_RD_ATTR(persistent_address, ISCSI_PERSISTENT_ADDRESS);
2041         SETUP_CONN_RD_ATTR(persistent_port, ISCSI_PERSISTENT_PORT);
2042         SETUP_CONN_RD_ATTR(ping_tmo, ISCSI_PING_TMO);
2043         SETUP_CONN_RD_ATTR(recv_tmo, ISCSI_RECV_TMO);
2044
2045         BUG_ON(count > ISCSI_CONN_ATTRS);
2046         priv->conn_attrs[count] = NULL;
2047         count = 0;
2048
2049         /* session parameters */
2050         priv->session_cont.ac.attrs = &priv->session_attrs[0];
2051         priv->session_cont.ac.class = &iscsi_session_class.class;
2052         priv->session_cont.ac.match = iscsi_session_match;
2053         transport_container_register(&priv->session_cont);
2054
2055         SETUP_SESSION_RD_ATTR(initial_r2t, ISCSI_INITIAL_R2T_EN);
2056         SETUP_SESSION_RD_ATTR(max_outstanding_r2t, ISCSI_MAX_R2T);
2057         SETUP_SESSION_RD_ATTR(immediate_data, ISCSI_IMM_DATA_EN);
2058         SETUP_SESSION_RD_ATTR(first_burst_len, ISCSI_FIRST_BURST);
2059         SETUP_SESSION_RD_ATTR(max_burst_len, ISCSI_MAX_BURST);
2060         SETUP_SESSION_RD_ATTR(data_pdu_in_order, ISCSI_PDU_INORDER_EN);
2061         SETUP_SESSION_RD_ATTR(data_seq_in_order, ISCSI_DATASEQ_INORDER_EN);
2062         SETUP_SESSION_RD_ATTR(erl, ISCSI_ERL);
2063         SETUP_SESSION_RD_ATTR(targetname, ISCSI_TARGET_NAME);
2064         SETUP_SESSION_RD_ATTR(tpgt, ISCSI_TPGT);
2065         SETUP_SESSION_RD_ATTR(password, ISCSI_USERNAME);
2066         SETUP_SESSION_RD_ATTR(password_in, ISCSI_USERNAME_IN);
2067         SETUP_SESSION_RD_ATTR(username, ISCSI_PASSWORD);
2068         SETUP_SESSION_RD_ATTR(username_in, ISCSI_PASSWORD_IN);
2069         SETUP_SESSION_RD_ATTR(fast_abort, ISCSI_FAST_ABORT);
2070         SETUP_SESSION_RD_ATTR(abort_tmo, ISCSI_ABORT_TMO);
2071         SETUP_SESSION_RD_ATTR(lu_reset_tmo,ISCSI_LU_RESET_TMO);
2072         SETUP_SESSION_RD_ATTR(tgt_reset_tmo,ISCSI_TGT_RESET_TMO);
2073         SETUP_SESSION_RD_ATTR(ifacename, ISCSI_IFACE_NAME);
2074         SETUP_SESSION_RD_ATTR(initiatorname, ISCSI_INITIATOR_NAME);
2075         SETUP_SESSION_RD_ATTR(targetalias, ISCSI_TARGET_ALIAS);
2076         SETUP_PRIV_SESSION_RW_ATTR(recovery_tmo);
2077         SETUP_PRIV_SESSION_RD_ATTR(state);
2078
2079         BUG_ON(count > ISCSI_SESSION_ATTRS);
2080         priv->session_attrs[count] = NULL;
2081
2082         spin_lock_irqsave(&iscsi_transport_lock, flags);
2083         list_add(&priv->list, &iscsi_transports);
2084         spin_unlock_irqrestore(&iscsi_transport_lock, flags);
2085
2086         printk(KERN_NOTICE "iscsi: registered transport (%s)\n", tt->name);
2087         return &priv->t;
2088
2089 unregister_dev:
2090         device_unregister(&priv->dev);
2091         return NULL;
2092 free_priv:
2093         kfree(priv);
2094         return NULL;
2095 }
2096 EXPORT_SYMBOL_GPL(iscsi_register_transport);
2097
2098 int iscsi_unregister_transport(struct iscsi_transport *tt)
2099 {
2100         struct iscsi_internal *priv;
2101         unsigned long flags;
2102
2103         BUG_ON(!tt);
2104
2105         mutex_lock(&rx_queue_mutex);
2106
2107         priv = iscsi_if_transport_lookup(tt);
2108         BUG_ON (!priv);
2109
2110         spin_lock_irqsave(&iscsi_transport_lock, flags);
2111         list_del(&priv->list);
2112         spin_unlock_irqrestore(&iscsi_transport_lock, flags);
2113
2114         transport_container_unregister(&priv->conn_cont);
2115         transport_container_unregister(&priv->session_cont);
2116         transport_container_unregister(&priv->t.host_attrs);
2117
2118         sysfs_remove_group(&priv->dev.kobj, &iscsi_transport_group);
2119         device_unregister(&priv->dev);
2120         mutex_unlock(&rx_queue_mutex);
2121
2122         return 0;
2123 }
2124 EXPORT_SYMBOL_GPL(iscsi_unregister_transport);
2125
2126 static __init int iscsi_transport_init(void)
2127 {
2128         int err;
2129
2130         printk(KERN_INFO "Loading iSCSI transport class v%s.\n",
2131                 ISCSI_TRANSPORT_VERSION);
2132
2133         atomic_set(&iscsi_session_nr, 0);
2134
2135         err = class_register(&iscsi_transport_class);
2136         if (err)
2137                 return err;
2138
2139         err = class_register(&iscsi_endpoint_class);
2140         if (err)
2141                 goto unregister_transport_class;
2142
2143         err = transport_class_register(&iscsi_host_class);
2144         if (err)
2145                 goto unregister_endpoint_class;
2146
2147         err = transport_class_register(&iscsi_connection_class);
2148         if (err)
2149                 goto unregister_host_class;
2150
2151         err = transport_class_register(&iscsi_session_class);
2152         if (err)
2153                 goto unregister_conn_class;
2154
2155         nls = netlink_kernel_create(&init_net, NETLINK_ISCSI, 1, iscsi_if_rx,
2156                                     NULL, THIS_MODULE);
2157         if (!nls) {
2158                 err = -ENOBUFS;
2159                 goto unregister_session_class;
2160         }
2161
2162         iscsi_eh_timer_workq = create_singlethread_workqueue("iscsi_eh");
2163         if (!iscsi_eh_timer_workq)
2164                 goto release_nls;
2165
2166         return 0;
2167
2168 release_nls:
2169         netlink_kernel_release(nls);
2170 unregister_session_class:
2171         transport_class_unregister(&iscsi_session_class);
2172 unregister_conn_class:
2173         transport_class_unregister(&iscsi_connection_class);
2174 unregister_host_class:
2175         transport_class_unregister(&iscsi_host_class);
2176 unregister_endpoint_class:
2177         class_unregister(&iscsi_endpoint_class);
2178 unregister_transport_class:
2179         class_unregister(&iscsi_transport_class);
2180         return err;
2181 }
2182
2183 static void __exit iscsi_transport_exit(void)
2184 {
2185         destroy_workqueue(iscsi_eh_timer_workq);
2186         netlink_kernel_release(nls);
2187         transport_class_unregister(&iscsi_connection_class);
2188         transport_class_unregister(&iscsi_session_class);
2189         transport_class_unregister(&iscsi_host_class);
2190         class_unregister(&iscsi_endpoint_class);
2191         class_unregister(&iscsi_transport_class);
2192 }
2193
2194 module_init(iscsi_transport_init);
2195 module_exit(iscsi_transport_exit);
2196
2197 MODULE_AUTHOR("Mike Christie <michaelc@cs.wisc.edu>, "
2198               "Dmitry Yusupov <dmitry_yus@yahoo.com>, "
2199               "Alex Aizman <itn780@yahoo.com>");
2200 MODULE_DESCRIPTION("iSCSI Transport Interface");
2201 MODULE_LICENSE("GPL");
2202 MODULE_VERSION(ISCSI_TRANSPORT_VERSION);