drivers/scsi/scsi_netlink.c

   1 /*
   2  *  scsi_netlink.c  - SCSI Transport Netlink Interface
   3  *
   4  *  Copyright (C) 2006   James Smart, Emulex Corporation
   5  *
   6  *  This program is free software; you can redistribute it and/or modify
   7  *  it under the terms of the GNU General Public License as published by
   8  *  the Free Software Foundation; either version 2 of the License, or
   9  *  (at your option) any later version.
  10  *
  11  *  This program is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *  GNU General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU General Public License
  17  *  along with this program; if not, write to the Free Software
  18  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19  *
  20  */
  21 #include <linux/time.h>
  22 #include <linux/jiffies.h>
  23 #include <linux/security.h>
  24 #include <linux/delay.h>
  25 #include <net/sock.h>
  26 #include <net/netlink.h>
  27
  28 #include <scsi/scsi_netlink.h>
  29 #include "scsi_priv.h"
  30
  31 struct sock *scsi_nl_sock = NULL;
  32 EXPORT_SYMBOL_GPL(scsi_nl_sock);
  33
  34 static DEFINE_SPINLOCK(scsi_nl_lock);
  35 static struct list_head scsi_nl_drivers;
  36
  37 static u32      scsi_nl_state;
  38 #define STATE_EHANDLER_BSY              0x00000001
  39
  40 struct scsi_nl_transport {
  41         int (*msg_handler)(struct sk_buff *);
  42         void (*event_handler)(struct notifier_block *, unsigned long, void *);
  43         unsigned int refcnt;
  44         int flags;
  45 };
  46
  47 /* flags values (bit flags) */
  48 #define HANDLER_DELETING                0x1
  49
  50 static struct scsi_nl_transport transports[SCSI_NL_MAX_TRANSPORTS] =
  51         { {NULL, }, };
  52
  53
  54 struct scsi_nl_drvr {
  55         struct list_head next;
  56         int (*dmsg_handler)(struct Scsi_Host *shost, void *payload,
  57                                  u32 len, u32 pid);
  58         void (*devt_handler)(struct notifier_block *nb,
  59                                  unsigned long event, void *notify_ptr);
  60         struct scsi_host_template *hostt;
  61         u64 vendor_id;
  62         unsigned int refcnt;
  63         int flags;
  64 };
  65
  66
  67
  68 /**
  69  * scsi_nl_rcv_msg - Receive message handler.
  70  * @skb:                socket receive buffer
  71  *
  72  * Description: Extracts message from a receive buffer.
  73  *    Validates message header and calls appropriate transport message handler
  74  *
  75  *
  76  **/
  77 static void
  78 scsi_nl_rcv_msg(struct sk_buff *skb)
  79 {
  80         struct nlmsghdr *nlh;
  81         struct scsi_nl_hdr *hdr;
  82         unsigned long flags;
  83         u32 rlen;
  84         int err, tport;
  85
  86         while (skb->len >= NLMSG_SPACE(0)) {
  87                 err = 0;
  88
  89                 nlh = nlmsg_hdr(skb);
  90                 if ((nlh->nlmsg_len < (sizeof(*nlh) + sizeof(*hdr))) ||
  91                     (skb->len < nlh->nlmsg_len)) {
  92                         printk(KERN_WARNING "%s: discarding partial skb\n",
  93                                  __func__);
  94                         return;
  95                 }
  96
  97                 rlen = NLMSG_ALIGN(nlh->nlmsg_len);
  98                 if (rlen > skb->len)
  99                         rlen = skb->len;
 100
 101                 if (nlh->nlmsg_type != SCSI_TRANSPORT_MSG) {
 102                         err = -EBADMSG;
 103                         goto next_msg;
 104                 }
 105
 106                 hdr = NLMSG_DATA(nlh);
 107                 if ((hdr->version != SCSI_NL_VERSION) ||
 108                     (hdr->magic != SCSI_NL_MAGIC)) {
 109                         err = -EPROTOTYPE;
 110                         goto next_msg;
 111                 }
 112
 113                 if (security_netlink_recv(skb, CAP_SYS_ADMIN)) {
 114                         err = -EPERM;
 115                         goto next_msg;
 116                 }
 117
 118                 if (nlh->nlmsg_len < (sizeof(*nlh) + hdr->msglen)) {
 119                         printk(KERN_WARNING "%s: discarding partial message\n",
 120                                  __func__);
 121                         goto next_msg;
 122                 }
 123
 124                 /*
 125                  * Deliver message to the appropriate transport
 126                  */
 127                 spin_lock_irqsave(&scsi_nl_lock, flags);
 128
 129                 tport = hdr->transport;
 130                 if ((tport < SCSI_NL_MAX_TRANSPORTS) &&
 131                     !(transports[tport].flags & HANDLER_DELETING) &&
 132                     (transports[tport].msg_handler)) {
 133                         transports[tport].refcnt++;
 134                         spin_unlock_irqrestore(&scsi_nl_lock, flags);
 135                         err = transports[tport].msg_handler(skb);
 136                         spin_lock_irqsave(&scsi_nl_lock, flags);
 137                         transports[tport].refcnt--;
 138                 } else
 139                         err = -ENOENT;
 140
 141                 spin_unlock_irqrestore(&scsi_nl_lock, flags);
 142
 143 next_msg:
 144                 if ((err) || (nlh->nlmsg_flags & NLM_F_ACK))
 145                         netlink_ack(skb, nlh, err);
 146
 147                 skb_pull(skb, rlen);
 148         }
 149 }
 150
 151
 152 /**
 153  * scsi_nl_rcv_event - Event handler for a netlink socket.
 154  * @this:               event notifier block
 155  * @event:              event type
 156  * @ptr:                event payload
 157  *
 158  **/
 159 static int
 160 scsi_nl_rcv_event(struct notifier_block *this, unsigned long event, void *ptr)
 161 {
 162         struct netlink_notify *n = ptr;
 163         struct scsi_nl_drvr *driver;
 164         unsigned long flags;
 165         int tport;
 166
 167         if (n->protocol != NETLINK_SCSITRANSPORT)
 168                 return NOTIFY_DONE;
 169
 170         spin_lock_irqsave(&scsi_nl_lock, flags);
 171         scsi_nl_state |= STATE_EHANDLER_BSY;
 172
 173         /*
 174          * Pass event on to any transports that may be listening
 175          */
 176         for (tport = 0; tport < SCSI_NL_MAX_TRANSPORTS; tport++) {
 177                 if (!(transports[tport].flags & HANDLER_DELETING) &&
 178                     (transports[tport].event_handler)) {
 179                         spin_unlock_irqrestore(&scsi_nl_lock, flags);
 180                         transports[tport].event_handler(this, event, ptr);
 181                         spin_lock_irqsave(&scsi_nl_lock, flags);
 182                 }
 183         }
 184
 185         /*
 186          * Pass event on to any drivers that may be listening
 187          */
 188         list_for_each_entry(driver, &scsi_nl_drivers, next) {
 189                 if (!(driver->flags & HANDLER_DELETING) &&
 190                     (driver->devt_handler)) {
 191                         spin_unlock_irqrestore(&scsi_nl_lock, flags);
 192                         driver->devt_handler(this, event, ptr);
 193                         spin_lock_irqsave(&scsi_nl_lock, flags);
 194                 }
 195         }
 196
 197         scsi_nl_state &= ~STATE_EHANDLER_BSY;
 198         spin_unlock_irqrestore(&scsi_nl_lock, flags);
 199
 200         return NOTIFY_DONE;
 201 }
 202
 203 static struct notifier_block scsi_netlink_notifier = {
 204         .notifier_call  = scsi_nl_rcv_event,
 205 };
 206
 207
 208 /*
 209  * GENERIC SCSI transport receive and event handlers
 210  */
 211
 212 /**
 213  * scsi_generic_msg_handler - receive message handler for GENERIC transport messages
 214  * @skb:                socket receive buffer
 215  **/
 216 static int
 217 scsi_generic_msg_handler(struct sk_buff *skb)
 218 {
 219         struct nlmsghdr *nlh = nlmsg_hdr(skb);
 220         struct scsi_nl_hdr *snlh = NLMSG_DATA(nlh);
 221         struct scsi_nl_drvr *driver;
 222         struct Scsi_Host *shost;
 223         unsigned long flags;
 224         int err = 0, match, pid;
 225
 226         pid = NETLINK_CREDS(skb)->pid;
 227
 228         switch (snlh->msgtype) {
 229         case SCSI_NL_SHOST_VENDOR:
 230                 {
 231                 struct scsi_nl_host_vendor_msg *msg = NLMSG_DATA(nlh);
 232
 233                 /* Locate the driver that corresponds to the message */
 234                 spin_lock_irqsave(&scsi_nl_lock, flags);
 235                 match = 0;
 236                 list_for_each_entry(driver, &scsi_nl_drivers, next) {
 237                         if (driver->vendor_id == msg->vendor_id) {
 238                                 match = 1;
 239                                 break;
 240                         }
 241                 }
 242
 243                 if ((!match) || (!driver->dmsg_handler)) {
 244                         spin_unlock_irqrestore(&scsi_nl_lock, flags);
 245                         err = -ESRCH;
 246                         goto rcv_exit;
 247                 }
 248
 249                 if (driver->flags & HANDLER_DELETING) {
 250                         spin_unlock_irqrestore(&scsi_nl_lock, flags);
 251                         err = -ESHUTDOWN;
 252                         goto rcv_exit;
 253                 }
 254
 255                 driver->refcnt++;
 256                 spin_unlock_irqrestore(&scsi_nl_lock, flags);
 257
 258
 259                 /* if successful, scsi_host_lookup takes a shost reference */
 260                 shost = scsi_host_lookup(msg->host_no);
 261                 if (!shost) {
 262                         err = -ENODEV;
 263                         goto driver_exit;
 264                 }
 265
 266                 /* is this host owned by the vendor ? */
 267                 if (shost->hostt != driver->hostt) {
 268                         err = -EINVAL;
 269                         goto vendormsg_put;
 270                 }
 271
 272                 /* pass message on to the driver */
 273                 err = driver->dmsg_handler(shost, (void *)&msg[1],
 274                                          msg->vmsg_datalen, pid);
 275
 276 vendormsg_put:
 277                 /* release reference by scsi_host_lookup */
 278                 scsi_host_put(shost);
 279
 280 driver_exit:
 281                 /* release our own reference on the registration object */
 282                 spin_lock_irqsave(&scsi_nl_lock, flags);
 283                 driver->refcnt--;
 284                 spin_unlock_irqrestore(&scsi_nl_lock, flags);
 285                 break;
 286                 }
 287
 288         default:
 289                 err = -EBADR;
 290                 break;
 291         }
 292
 293 rcv_exit:
 294         if (err)
 295                 printk(KERN_WARNING "%s: Msgtype %d failed - err %d\n",
 296                          __func__, snlh->msgtype, err);
 297         return err;
 298 }
 299
 300
 301 /**
 302  * scsi_nl_add_transport -
 303  *    Registers message and event handlers for a transport. Enables
 304  *    receipt of netlink messages and events to a transport.
 305  *
 306  * @tport:              transport registering handlers
 307  * @msg_handler:        receive message handler callback
 308  * @event_handler:      receive event handler callback
 309  **/
 310 int
 311 scsi_nl_add_transport(u8 tport,
 312         int (*msg_handler)(struct sk_buff *),
 313         void (*event_handler)(struct notifier_block *, unsigned long, void *))
 314 {
 315         unsigned long flags;
 316         int err = 0;
 317
 318         if (tport >= SCSI_NL_MAX_TRANSPORTS)
 319                 return -EINVAL;
 320
 321         spin_lock_irqsave(&scsi_nl_lock, flags);
 322
 323         if (scsi_nl_state & STATE_EHANDLER_BSY) {
 324                 spin_unlock_irqrestore(&scsi_nl_lock, flags);
 325                 msleep(1);
 326                 spin_lock_irqsave(&scsi_nl_lock, flags);
 327         }
 328
 329         if (transports[tport].msg_handler || transports[tport].event_handler) {
 330                 err = -EALREADY;
 331                 goto register_out;
 332         }
 333
 334         transports[tport].msg_handler = msg_handler;
 335         transports[tport].event_handler = event_handler;
 336         transports[tport].flags = 0;
 337         transports[tport].refcnt = 0;
 338
 339 register_out:
 340         spin_unlock_irqrestore(&scsi_nl_lock, flags);
 341
 342         return err;
 343 }
 344 EXPORT_SYMBOL_GPL(scsi_nl_add_transport);
 345
 346
 347 /**
 348  * scsi_nl_remove_transport -
 349  *    Disable transport receiption of messages and events
 350  *
 351  * @tport:              transport deregistering handlers
 352  *
 353  **/
 354 void
 355 scsi_nl_remove_transport(u8 tport)
 356 {
 357         unsigned long flags;
 358
 359         spin_lock_irqsave(&scsi_nl_lock, flags);
 360         if (scsi_nl_state & STATE_EHANDLER_BSY) {
 361                 spin_unlock_irqrestore(&scsi_nl_lock, flags);
 362                 msleep(1);
 363                 spin_lock_irqsave(&scsi_nl_lock, flags);
 364         }
 365
 366         if (tport < SCSI_NL_MAX_TRANSPORTS) {
 367                 transports[tport].flags |= HANDLER_DELETING;
 368
 369                 while (transports[tport].refcnt != 0) {
 370                         spin_unlock_irqrestore(&scsi_nl_lock, flags);
 371                         schedule_timeout_uninterruptible(HZ/4);
 372                         spin_lock_irqsave(&scsi_nl_lock, flags);
 373                 }
 374                 transports[tport].msg_handler = NULL;
 375                 transports[tport].event_handler = NULL;
 376                 transports[tport].flags = 0;
 377         }
 378
 379         spin_unlock_irqrestore(&scsi_nl_lock, flags);
 380
 381         return;
 382 }
 383 EXPORT_SYMBOL_GPL(scsi_nl_remove_transport);
 384
 385
 386 /**
 387  * scsi_nl_add_driver -
 388  *    A driver is registering its interfaces for SCSI netlink messages
 389  *
 390  * @vendor_id:          A unique identification value for the driver.
 391  * @hostt:              address of the driver's host template. Used
 392  *                      to verify an shost is bound to the driver
 393  * @nlmsg_handler:      receive message handler callback
 394  * @nlevt_handler:      receive event handler callback
 395  *
 396  * Returns:
 397  *   0 on Success
 398  *   error result otherwise
 399  **/
 400 int
 401 scsi_nl_add_driver(u64 vendor_id, struct scsi_host_template *hostt,
 402         int (*nlmsg_handler)(struct Scsi_Host *shost, void *payload,
 403                                  u32 len, u32 pid),
 404         void (*nlevt_handler)(struct notifier_block *nb,
 405                                  unsigned long event, void *notify_ptr))
 406 {
 407         struct scsi_nl_drvr *driver;
 408         unsigned long flags;
 409
 410         driver = kzalloc(sizeof(*driver), GFP_KERNEL);
 411         if (unlikely(!driver)) {
 412                 printk(KERN_ERR "%s: allocation failure\n", __func__);
 413                 return -ENOMEM;
 414         }
 415
 416         driver->dmsg_handler = nlmsg_handler;
 417         driver->devt_handler = nlevt_handler;
 418         driver->hostt = hostt;
 419         driver->vendor_id = vendor_id;
 420
 421         spin_lock_irqsave(&scsi_nl_lock, flags);
 422         if (scsi_nl_state & STATE_EHANDLER_BSY) {
 423                 spin_unlock_irqrestore(&scsi_nl_lock, flags);
 424                 msleep(1);
 425                 spin_lock_irqsave(&scsi_nl_lock, flags);
 426         }
 427         list_add_tail(&driver->next, &scsi_nl_drivers);
 428         spin_unlock_irqrestore(&scsi_nl_lock, flags);
 429
 430         return 0;
 431 }
 432 EXPORT_SYMBOL_GPL(scsi_nl_add_driver);
 433
 434
 435 /**
 436  * scsi_nl_remove_driver -
 437  *    An driver is unregistering with the SCSI netlink messages
 438  *
 439  * @vendor_id:          The unique identification value for the driver.
 440  **/
 441 void
 442 scsi_nl_remove_driver(u64 vendor_id)
 443 {
 444         struct scsi_nl_drvr *driver;
 445         unsigned long flags;
 446
 447         spin_lock_irqsave(&scsi_nl_lock, flags);
 448         if (scsi_nl_state & STATE_EHANDLER_BSY) {
 449                 spin_unlock_irqrestore(&scsi_nl_lock, flags);
 450                 msleep(1);
 451                 spin_lock_irqsave(&scsi_nl_lock, flags);
 452         }
 453
 454         list_for_each_entry(driver, &scsi_nl_drivers, next) {
 455                 if (driver->vendor_id == vendor_id) {
 456                         driver->flags |= HANDLER_DELETING;
 457                         while (driver->refcnt != 0) {
 458                                 spin_unlock_irqrestore(&scsi_nl_lock, flags);
 459                                 schedule_timeout_uninterruptible(HZ/4);
 460                                 spin_lock_irqsave(&scsi_nl_lock, flags);
 461                         }
 462                         list_del(&driver->next);
 463                         kfree(driver);
 464                         spin_unlock_irqrestore(&scsi_nl_lock, flags);
 465                         return;
 466                 }
 467         }
 468
 469         spin_unlock_irqrestore(&scsi_nl_lock, flags);
 470
 471         printk(KERN_ERR "%s: removal of driver failed - vendor_id 0x%llx\n",
 472                __func__, (unsigned long long)vendor_id);
 473         return;
 474 }
 475 EXPORT_SYMBOL_GPL(scsi_nl_remove_driver);
 476
 477
 478 /**
 479  * scsi_netlink_init - Called by SCSI subsystem to intialize
 480  *      the SCSI transport netlink interface
 481  *
 482  **/
 483 void
 484 scsi_netlink_init(void)
 485 {
 486         int error;
 487
 488         INIT_LIST_HEAD(&scsi_nl_drivers);
 489
 490         error = netlink_register_notifier(&scsi_netlink_notifier);
 491         if (error) {
 492                 printk(KERN_ERR "%s: register of event handler failed - %d\n",
 493                                 __func__, error);
 494                 return;
 495         }
 496
 497         scsi_nl_sock = netlink_kernel_create(&init_net, NETLINK_SCSITRANSPORT,
 498                                 SCSI_NL_GRP_CNT, scsi_nl_rcv_msg, NULL,
 499                                 THIS_MODULE);
 500         if (!scsi_nl_sock) {
 501                 printk(KERN_ERR "%s: register of recieve handler failed\n",
 502                                 __func__);
 503                 netlink_unregister_notifier(&scsi_netlink_notifier);
 504                 return;
 505         }
 506
 507         /* Register the entry points for the generic SCSI transport */
 508         error = scsi_nl_add_transport(SCSI_NL_TRANSPORT,
 509                                 scsi_generic_msg_handler, NULL);
 510         if (error)
 511                 printk(KERN_ERR "%s: register of GENERIC transport handler"
 512                                 "  failed - %d\n", __func__, error);
 513         return;
 514 }
 515
 516
 517 /**
 518  * scsi_netlink_exit - Called by SCSI subsystem to disable the SCSI transport netlink interface
 519  *
 520  **/
 521 void
 522 scsi_netlink_exit(void)
 523 {
 524         scsi_nl_remove_transport(SCSI_NL_TRANSPORT);
 525
 526         if (scsi_nl_sock) {
 527                 netlink_kernel_release(scsi_nl_sock);
 528                 netlink_unregister_notifier(&scsi_netlink_notifier);
 529         }
 530
 531         return;
 532 }
 533
 534
 535 /*
 536  * Exported Interfaces
 537  */
 538
 539 /**
 540  * scsi_nl_send_transport_msg -
 541  *    Generic function to send a single message from a SCSI transport to
 542  *    a single process
 543  *
 544  * @pid:                receiving pid
 545  * @hdr:                message payload
 546  *
 547  **/
 548 void
 549 scsi_nl_send_transport_msg(u32 pid, struct scsi_nl_hdr *hdr)
 550 {
 551         struct sk_buff *skb;
 552         struct nlmsghdr *nlh;
 553         const char *fn;
 554         char *datab;
 555         u32 len, skblen;
 556         int err;
 557
 558         if (!scsi_nl_sock) {
 559                 err = -ENOENT;
 560                 fn = "netlink socket";
 561                 goto msg_fail;
 562         }
 563
 564         len = NLMSG_SPACE(hdr->msglen);
 565         skblen = NLMSG_SPACE(len);
 566
 567         skb = alloc_skb(skblen, GFP_KERNEL);
 568         if (!skb) {
 569                 err = -ENOBUFS;
 570                 fn = "alloc_skb";
 571                 goto msg_fail;
 572         }
 573
 574         nlh = nlmsg_put(skb, pid, 0, SCSI_TRANSPORT_MSG, len - sizeof(*nlh), 0);
 575         if (!nlh) {
 576                 err = -ENOBUFS;
 577                 fn = "nlmsg_put";
 578                 goto msg_fail_skb;
 579         }
 580         datab = NLMSG_DATA(nlh);
 581         memcpy(datab, hdr, hdr->msglen);
 582
 583         err = nlmsg_unicast(scsi_nl_sock, skb, pid);
 584         if (err < 0) {
 585                 fn = "nlmsg_unicast";
 586                 /* nlmsg_unicast already kfree_skb'd */
 587                 goto msg_fail;
 588         }
 589
 590         return;
 591
 592 msg_fail_skb:
 593         kfree_skb(skb);
 594 msg_fail:
 595         printk(KERN_WARNING
 596                 "%s: Dropped Message : pid %d Transport %d, msgtype x%x, "
 597                 "msglen %d: %s : err %d\n",
 598                 __func__, pid, hdr->transport, hdr->msgtype, hdr->msglen,
 599                 fn, err);
 600         return;
 601 }
 602 EXPORT_SYMBOL_GPL(scsi_nl_send_transport_msg);
 603
 604
 605 /**
 606  * scsi_nl_send_vendor_msg - called to send a shost vendor unique message
 607  *                      to a specific process id.
 608  *
 609  * @pid:                process id of the receiver
 610  * @host_no:            host # sending the message
 611  * @vendor_id:          unique identifier for the driver's vendor
 612  * @data_len:           amount, in bytes, of vendor unique payload data
 613  * @data_buf:           pointer to vendor unique data buffer
 614  *
 615  * Returns:
 616  *   0 on succesful return
 617  *   otherwise, failing error code
 618  *
 619  * Notes:
 620  *      This routine assumes no locks are held on entry.
 621  */
 622 int
 623 scsi_nl_send_vendor_msg(u32 pid, unsigned short host_no, u64 vendor_id,
 624                          char *data_buf, u32 data_len)
 625 {
 626         struct sk_buff *skb;
 627         struct nlmsghdr *nlh;
 628         struct scsi_nl_host_vendor_msg *msg;
 629         u32 len, skblen;
 630         int err;
 631
 632         if (!scsi_nl_sock) {
 633                 err = -ENOENT;
 634                 goto send_vendor_fail;
 635         }
 636
 637         len = SCSI_NL_MSGALIGN(sizeof(*msg) + data_len);
 638         skblen = NLMSG_SPACE(len);
 639
 640         skb = alloc_skb(skblen, GFP_KERNEL);
 641         if (!skb) {
 642                 err = -ENOBUFS;
 643                 goto send_vendor_fail;
 644         }
 645
 646         nlh = nlmsg_put(skb, 0, 0, SCSI_TRANSPORT_MSG,
 647                                 skblen - sizeof(*nlh), 0);
 648         if (!nlh) {
 649                 err = -ENOBUFS;
 650                 goto send_vendor_fail_skb;
 651         }
 652         msg = NLMSG_DATA(nlh);
 653
 654         INIT_SCSI_NL_HDR(&msg->snlh, SCSI_NL_TRANSPORT,
 655                                 SCSI_NL_SHOST_VENDOR, len);
 656         msg->vendor_id = vendor_id;
 657         msg->host_no = host_no;
 658         msg->vmsg_datalen = data_len;   /* bytes */
 659         memcpy(&msg[1], data_buf, data_len);
 660
 661         err = nlmsg_unicast(scsi_nl_sock, skb, pid);
 662         if (err)
 663                 /* nlmsg_multicast already kfree_skb'd */
 664                 goto send_vendor_fail;
 665
 666         return 0;
 667
 668 send_vendor_fail_skb:
 669         kfree_skb(skb);
 670 send_vendor_fail:
 671         printk(KERN_WARNING
 672                 "%s: Dropped SCSI Msg : host %d vendor_unique - err %d\n",
 673                 __func__, host_no, err);
 674         return err;
 675 }
 676 EXPORT_SYMBOL(scsi_nl_send_vendor_msg);
 677
 678