git.oblomov.eu Git - linux-2.6/blob - 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
 214  *                       messages
 215  *
 216  * @skb:                socket receive buffer
 217  *
 218  **/
 219 static int
 220 scsi_generic_msg_handler(struct sk_buff *skb)
 221 {
 222         struct nlmsghdr *nlh = nlmsg_hdr(skb);
 223         struct scsi_nl_hdr *snlh = NLMSG_DATA(nlh);
 224         struct scsi_nl_drvr *driver;
 225         struct Scsi_Host *shost;
 226         unsigned long flags;
 227         int err = 0, match, pid;
 228
 229         pid = NETLINK_CREDS(skb)->pid;
 230
 231         switch (snlh->msgtype) {
 232         case SCSI_NL_SHOST_VENDOR:
 233                 {
 234                 struct scsi_nl_host_vendor_msg *msg = NLMSG_DATA(nlh);
 235
 236                 /* Locate the driver that corresponds to the message */
 237                 spin_lock_irqsave(&scsi_nl_lock, flags);
 238                 match = 0;
 239                 list_for_each_entry(driver, &scsi_nl_drivers, next) {
 240                         if (driver->vendor_id == msg->vendor_id) {
 241                                 match = 1;
 242                                 break;
 243                         }
 244                 }
 245
 246                 if ((!match) || (!driver->dmsg_handler)) {
 247                         spin_unlock_irqrestore(&scsi_nl_lock, flags);
 248                         err = -ESRCH;
 249                         goto rcv_exit;
 250                 }
 251
 252                 if (driver->flags & HANDLER_DELETING) {
 253                         spin_unlock_irqrestore(&scsi_nl_lock, flags);
 254                         err = -ESHUTDOWN;
 255                         goto rcv_exit;
 256                 }
 257
 258                 driver->refcnt++;
 259                 spin_unlock_irqrestore(&scsi_nl_lock, flags);
 260
 261
 262                 /* if successful, scsi_host_lookup takes a shost reference */
 263                 shost = scsi_host_lookup(msg->host_no);
 264                 if (!shost) {
 265                         err = -ENODEV;
 266                         goto driver_exit;
 267                 }
 268
 269                 /* is this host owned by the vendor ? */
 270                 if (shost->hostt != driver->hostt) {
 271                         err = -EINVAL;
 272                         goto vendormsg_put;
 273                 }
 274
 275                 /* pass message on to the driver */
 276                 err = driver->dmsg_handler(shost, (void *)&msg[1],
 277                                          msg->vmsg_datalen, pid);
 278
 279 vendormsg_put:
 280                 /* release reference by scsi_host_lookup */
 281                 scsi_host_put(shost);
 282
 283 driver_exit:
 284                 /* release our own reference on the registration object */
 285                 spin_lock_irqsave(&scsi_nl_lock, flags);
 286                 driver->refcnt--;
 287                 spin_unlock_irqrestore(&scsi_nl_lock, flags);
 288                 break;
 289                 }
 290
 291         default:
 292                 err = -EBADR;
 293                 break;
 294         }
 295
 296 rcv_exit:
 297         if (err)
 298                 printk(KERN_WARNING "%s: Msgtype %d failed - err %d\n",
 299                          __func__, snlh->msgtype, err);
 300         return err;
 301 }
 302
 303
 304 /**
 305  * scsi_nl_add_transport -
 306  *    Registers message and event handlers for a transport. Enables
 307  *    receipt of netlink messages and events to a transport.
 308  *
 309  * @tport:              transport registering handlers
 310  * @msg_handler:        receive message handler callback
 311  * @event_handler:      receive event handler callback
 312  **/
 313 int
 314 scsi_nl_add_transport(u8 tport,
 315         int (*msg_handler)(struct sk_buff *),
 316         void (*event_handler)(struct notifier_block *, unsigned long, void *))
 317 {
 318         unsigned long flags;
 319         int err = 0;
 320
 321         if (tport >= SCSI_NL_MAX_TRANSPORTS)
 322                 return -EINVAL;
 323
 324         spin_lock_irqsave(&scsi_nl_lock, flags);
 325
 326         if (scsi_nl_state & STATE_EHANDLER_BSY) {
 327                 spin_unlock_irqrestore(&scsi_nl_lock, flags);
 328                 msleep(1);
 329                 spin_lock_irqsave(&scsi_nl_lock, flags);
 330         }
 331
 332         if (transports[tport].msg_handler || transports[tport].event_handler) {
 333                 err = -EALREADY;
 334                 goto register_out;
 335         }
 336
 337         transports[tport].msg_handler = msg_handler;
 338         transports[tport].event_handler = event_handler;
 339         transports[tport].flags = 0;
 340         transports[tport].refcnt = 0;
 341
 342 register_out:
 343         spin_unlock_irqrestore(&scsi_nl_lock, flags);
 344
 345         return err;
 346 }
 347 EXPORT_SYMBOL_GPL(scsi_nl_add_transport);
 348
 349
 350 /**
 351  * scsi_nl_remove_transport -
 352  *    Disable transport receiption of messages and events
 353  *
 354  * @tport:              transport deregistering handlers
 355  *
 356  **/
 357 void
 358 scsi_nl_remove_transport(u8 tport)
 359 {
 360         unsigned long flags;
 361
 362         spin_lock_irqsave(&scsi_nl_lock, flags);
 363         if (scsi_nl_state & STATE_EHANDLER_BSY) {
 364                 spin_unlock_irqrestore(&scsi_nl_lock, flags);
 365                 msleep(1);
 366                 spin_lock_irqsave(&scsi_nl_lock, flags);
 367         }
 368
 369         if (tport < SCSI_NL_MAX_TRANSPORTS) {
 370                 transports[tport].flags |= HANDLER_DELETING;
 371
 372                 while (transports[tport].refcnt != 0) {
 373                         spin_unlock_irqrestore(&scsi_nl_lock, flags);
 374                         schedule_timeout_uninterruptible(HZ/4);
 375                         spin_lock_irqsave(&scsi_nl_lock, flags);
 376                 }
 377                 transports[tport].msg_handler = NULL;
 378                 transports[tport].event_handler = NULL;
 379                 transports[tport].flags = 0;
 380         }
 381
 382         spin_unlock_irqrestore(&scsi_nl_lock, flags);
 383
 384         return;
 385 }
 386 EXPORT_SYMBOL_GPL(scsi_nl_remove_transport);
 387
 388
 389 /**
 390  * scsi_nl_add_driver -
 391  *    A driver is registering its interfaces for SCSI netlink messages
 392  *
 393  * @vendor_id:          A unique identification value for the driver.
 394  * @hostt:              address of the driver's host template. Used
 395  *                      to verify an shost is bound to the driver
 396  * @nlmsg_handler:      receive message handler callback
 397  * @nlevt_handler:      receive event handler callback
 398  *
 399  * Returns:
 400  *   0 on Success
 401  *   error result otherwise
 402  **/
 403 int
 404 scsi_nl_add_driver(u64 vendor_id, struct scsi_host_template *hostt,
 405         int (*nlmsg_handler)(struct Scsi_Host *shost, void *payload,
 406                                  u32 len, u32 pid),
 407         void (*nlevt_handler)(struct notifier_block *nb,
 408                                  unsigned long event, void *notify_ptr))
 409 {
 410         struct scsi_nl_drvr *driver;
 411         unsigned long flags;
 412
 413         driver = kzalloc(sizeof(*driver), GFP_KERNEL);
 414         if (unlikely(!driver)) {
 415                 printk(KERN_ERR "%s: allocation failure\n", __func__);
 416                 return -ENOMEM;
 417         }
 418
 419         driver->dmsg_handler = nlmsg_handler;
 420         driver->devt_handler = nlevt_handler;
 421         driver->hostt = hostt;
 422         driver->vendor_id = vendor_id;
 423
 424         spin_lock_irqsave(&scsi_nl_lock, flags);
 425         if (scsi_nl_state & STATE_EHANDLER_BSY) {
 426                 spin_unlock_irqrestore(&scsi_nl_lock, flags);
 427                 msleep(1);
 428                 spin_lock_irqsave(&scsi_nl_lock, flags);
 429         }
 430         list_add_tail(&driver->next, &scsi_nl_drivers);
 431         spin_unlock_irqrestore(&scsi_nl_lock, flags);
 432
 433         return 0;
 434 }
 435 EXPORT_SYMBOL_GPL(scsi_nl_add_driver);
 436
 437
 438 /**
 439  * scsi_nl_remove_driver -
 440  *    An driver is unregistering with the SCSI netlink messages
 441  *
 442  * @vendor_id:          The unique identification value for the driver.
 443  **/
 444 void
 445 scsi_nl_remove_driver(u64 vendor_id)
 446 {
 447         struct scsi_nl_drvr *driver;
 448         unsigned long flags;
 449
 450         spin_lock_irqsave(&scsi_nl_lock, flags);
 451         if (scsi_nl_state & STATE_EHANDLER_BSY) {
 452                 spin_unlock_irqrestore(&scsi_nl_lock, flags);
 453                 msleep(1);
 454                 spin_lock_irqsave(&scsi_nl_lock, flags);
 455         }
 456
 457         list_for_each_entry(driver, &scsi_nl_drivers, next) {
 458                 if (driver->vendor_id == vendor_id) {
 459                         driver->flags |= HANDLER_DELETING;
 460                         while (driver->refcnt != 0) {
 461                                 spin_unlock_irqrestore(&scsi_nl_lock, flags);
 462                                 schedule_timeout_uninterruptible(HZ/4);
 463                                 spin_lock_irqsave(&scsi_nl_lock, flags);
 464                         }
 465                         list_del(&driver->next);
 466                         kfree(driver);
 467                         spin_unlock_irqrestore(&scsi_nl_lock, flags);
 468                         return;
 469                 }
 470         }
 471
 472         spin_unlock_irqrestore(&scsi_nl_lock, flags);
 473
 474         printk(KERN_ERR "%s: removal of driver failed - vendor_id 0x%llx\n",
 475                __func__, (unsigned long long)vendor_id);
 476         return;
 477 }
 478 EXPORT_SYMBOL_GPL(scsi_nl_remove_driver);
 479
 480
 481 /**
 482  * scsi_netlink_init - Called by SCSI subsystem to intialize
 483  *      the SCSI transport netlink interface
 484  *
 485  **/
 486 void
 487 scsi_netlink_init(void)
 488 {
 489         int error;
 490
 491         INIT_LIST_HEAD(&scsi_nl_drivers);
 492
 493         error = netlink_register_notifier(&scsi_netlink_notifier);
 494         if (error) {
 495                 printk(KERN_ERR "%s: register of event handler failed - %d\n",
 496                                 __func__, error);
 497                 return;
 498         }
 499
 500         scsi_nl_sock = netlink_kernel_create(&init_net, NETLINK_SCSITRANSPORT,
 501                                 SCSI_NL_GRP_CNT, scsi_nl_rcv_msg, NULL,
 502                                 THIS_MODULE);
 503         if (!scsi_nl_sock) {
 504                 printk(KERN_ERR "%s: register of recieve handler failed\n",
 505                                 __func__);
 506                 netlink_unregister_notifier(&scsi_netlink_notifier);
 507                 return;
 508         }
 509
 510         /* Register the entry points for the generic SCSI transport */
 511         error = scsi_nl_add_transport(SCSI_NL_TRANSPORT,
 512                                 scsi_generic_msg_handler, NULL);
 513         if (error)
 514                 printk(KERN_ERR "%s: register of GENERIC transport handler"
 515                                 "  failed - %d\n", __func__, error);
 516         return;
 517 }
 518
 519
 520 /**
 521  * scsi_netlink_exit - Called by SCSI subsystem to disable the SCSI transport netlink interface
 522  *
 523  **/
 524 void
 525 scsi_netlink_exit(void)
 526 {
 527         scsi_nl_remove_transport(SCSI_NL_TRANSPORT);
 528
 529         if (scsi_nl_sock) {
 530                 netlink_kernel_release(scsi_nl_sock);
 531                 netlink_unregister_notifier(&scsi_netlink_notifier);
 532         }
 533
 534         return;
 535 }
 536
 537
 538 /*
 539  * Exported Interfaces
 540  */
 541
 542 /**
 543  * scsi_nl_send_transport_msg -
 544  *    Generic function to send a single message from a SCSI transport to
 545  *    a single process
 546  *
 547  * @pid:                receiving pid
 548  * @hdr:                message payload
 549  *
 550  **/
 551 void
 552 scsi_nl_send_transport_msg(u32 pid, struct scsi_nl_hdr *hdr)
 553 {
 554         struct sk_buff *skb;
 555         struct nlmsghdr *nlh;
 556         const char *fn;
 557         char *datab;
 558         u32 len, skblen;
 559         int err;
 560
 561         if (!scsi_nl_sock) {
 562                 err = -ENOENT;
 563                 fn = "netlink socket";
 564                 goto msg_fail;
 565         }
 566
 567         len = NLMSG_SPACE(hdr->msglen);
 568         skblen = NLMSG_SPACE(len);
 569
 570         skb = alloc_skb(skblen, GFP_KERNEL);
 571         if (!skb) {
 572                 err = -ENOBUFS;
 573                 fn = "alloc_skb";
 574                 goto msg_fail;
 575         }
 576
 577         nlh = nlmsg_put(skb, pid, 0, SCSI_TRANSPORT_MSG, len - sizeof(*nlh), 0);
 578         if (!nlh) {
 579                 err = -ENOBUFS;
 580                 fn = "nlmsg_put";
 581                 goto msg_fail_skb;
 582         }
 583         datab = NLMSG_DATA(nlh);
 584         memcpy(datab, hdr, hdr->msglen);
 585
 586         err = nlmsg_unicast(scsi_nl_sock, skb, pid);
 587         if (err < 0) {
 588                 fn = "nlmsg_unicast";
 589                 /* nlmsg_unicast already kfree_skb'd */
 590                 goto msg_fail;
 591         }
 592
 593         return;
 594
 595 msg_fail_skb:
 596         kfree_skb(skb);
 597 msg_fail:
 598         printk(KERN_WARNING
 599                 "%s: Dropped Message : pid %d Transport %d, msgtype x%x, "
 600                 "msglen %d: %s : err %d\n",
 601                 __func__, pid, hdr->transport, hdr->msgtype, hdr->msglen,
 602                 fn, err);
 603         return;
 604 }
 605 EXPORT_SYMBOL_GPL(scsi_nl_send_transport_msg);
 606
 607
 608 /**
 609  * scsi_nl_send_vendor_msg - called to send a shost vendor unique message
 610  *                      to a specific process id.
 611  *
 612  * @pid:                process id of the receiver
 613  * @host_no:            host # sending the message
 614  * @vendor_id:          unique identifier for the driver's vendor
 615  * @data_len:           amount, in bytes, of vendor unique payload data
 616  * @data_buf:           pointer to vendor unique data buffer
 617  *
 618  * Returns:
 619  *   0 on succesful return
 620  *   otherwise, failing error code
 621  *
 622  * Notes:
 623  *      This routine assumes no locks are held on entry.
 624  */
 625 int
 626 scsi_nl_send_vendor_msg(u32 pid, unsigned short host_no, u64 vendor_id,
 627                          char *data_buf, u32 data_len)
 628 {
 629         struct sk_buff *skb;
 630         struct nlmsghdr *nlh;
 631         struct scsi_nl_host_vendor_msg *msg;
 632         u32 len, skblen;
 633         int err;
 634
 635         if (!scsi_nl_sock) {
 636                 err = -ENOENT;
 637                 goto send_vendor_fail;
 638         }
 639
 640         len = SCSI_NL_MSGALIGN(sizeof(*msg) + data_len);
 641         skblen = NLMSG_SPACE(len);
 642
 643         skb = alloc_skb(skblen, GFP_KERNEL);
 644         if (!skb) {
 645                 err = -ENOBUFS;
 646                 goto send_vendor_fail;
 647         }
 648
 649         nlh = nlmsg_put(skb, 0, 0, SCSI_TRANSPORT_MSG,
 650                                 skblen - sizeof(*nlh), 0);
 651         if (!nlh) {
 652                 err = -ENOBUFS;
 653                 goto send_vendor_fail_skb;
 654         }
 655         msg = NLMSG_DATA(nlh);
 656
 657         INIT_SCSI_NL_HDR(&msg->snlh, SCSI_NL_TRANSPORT,
 658                                 SCSI_NL_SHOST_VENDOR, len);
 659         msg->vendor_id = vendor_id;
 660         msg->host_no = host_no;
 661         msg->vmsg_datalen = data_len;   /* bytes */
 662         memcpy(&msg[1], data_buf, data_len);
 663
 664         err = nlmsg_unicast(scsi_nl_sock, skb, pid);
 665         if (err)
 666                 /* nlmsg_multicast already kfree_skb'd */
 667                 goto send_vendor_fail;
 668
 669         return 0;
 670
 671 send_vendor_fail_skb:
 672         kfree_skb(skb);
 673 send_vendor_fail:
 674         printk(KERN_WARNING
 675                 "%s: Dropped SCSI Msg : host %d vendor_unique - err %d\n",
 676                 __func__, host_no, err);
 677         return err;
 678 }
 679 EXPORT_SYMBOL(scsi_nl_send_vendor_msg);
 680
 681