nbd.c

   1 /*
   2  *  Copyright (C) 2005  Anthony Liguori <anthony@codemonkey.ws>
   3  *
   4  *  Network Block Device
   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; under version 2 of the License.
   9  *
  10  *  This program is distributed in the hope that it will be useful,
  11  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  *  GNU General Public License for more details.
  14  *
  15  *  You should have received a copy of the GNU General Public License
  16  *  along with this program; if not, see <http://www.gnu.org/licenses/>.
  17  */
  18
  19 #include "nbd.h"
  20
  21 #include <errno.h>
  22 #include <string.h>
  23 #ifndef _WIN32
  24 #include <sys/ioctl.h>
  25 #endif
  26 #ifdef __sun__
  27 #include <sys/ioccom.h>
  28 #endif
  29 #include <ctype.h>
  30 #include <inttypes.h>
  31
  32 #include "qemu_socket.h"
  33
  34 //#define DEBUG_NBD
  35
  36 #ifdef DEBUG_NBD
  37 #define TRACE(msg, ...) do { \
  38     LOG(msg, ## __VA_ARGS__); \
  39 } while(0)
  40 #else
  41 #define TRACE(msg, ...) \
  42     do { } while (0)
  43 #endif
  44
  45 #define LOG(msg, ...) do { \
  46     fprintf(stderr, "%s:%s():L%d: " msg "\n", \
  47             __FILE__, __FUNCTION__, __LINE__, ## __VA_ARGS__); \
  48 } while(0)
  49
  50 /* This is all part of the "official" NBD API */
  51
  52 #define NBD_REQUEST_MAGIC       0x25609513
  53 #define NBD_REPLY_MAGIC         0x67446698
  54
  55 #define NBD_SET_SOCK            _IO(0xab, 0)
  56 #define NBD_SET_BLKSIZE         _IO(0xab, 1)
  57 #define NBD_SET_SIZE            _IO(0xab, 2)
  58 #define NBD_DO_IT               _IO(0xab, 3)
  59 #define NBD_CLEAR_SOCK          _IO(0xab, 4)
  60 #define NBD_CLEAR_QUE           _IO(0xab, 5)
  61 #define NBD_PRINT_DEBUG         _IO(0xab, 6)
  62 #define NBD_SET_SIZE_BLOCKS     _IO(0xab, 7)
  63 #define NBD_DISCONNECT          _IO(0xab, 8)
  64
  65 #define NBD_OPT_EXPORT_NAME     (1 << 0)
  66
  67 /* That's all folks */
  68
  69 #define read_sync(fd, buffer, size) nbd_wr_sync(fd, buffer, size, true)
  70 #define write_sync(fd, buffer, size) nbd_wr_sync(fd, buffer, size, false)
  71
  72 size_t nbd_wr_sync(int fd, void *buffer, size_t size, bool do_read)
  73 {
  74     size_t offset = 0;
  75
  76     while (offset < size) {
  77         ssize_t len;
  78
  79         if (do_read) {
  80             len = recv(fd, buffer + offset, size - offset, 0);
  81         } else {
  82             len = send(fd, buffer + offset, size - offset, 0);
  83         }
  84
  85         if (len == -1)
  86             errno = socket_error();
  87
  88         /* recoverable error */
  89         if (len == -1 && (errno == EAGAIN || errno == EINTR)) {
  90             continue;
  91         }
  92
  93         /* eof */
  94         if (len == 0) {
  95             break;
  96         }
  97
  98         /* unrecoverable error */
  99         if (len == -1) {
 100             return 0;
 101         }
 102
 103         offset += len;
 104     }
 105
 106     return offset;
 107 }
 108
 109 int tcp_socket_outgoing(const char *address, uint16_t port)
 110 {
 111     int s;
 112     struct in_addr in;
 113     struct sockaddr_in addr;
 114
 115     s = socket(PF_INET, SOCK_STREAM, 0);
 116     if (s == -1) {
 117         return -1;
 118     }
 119
 120     if (inet_aton(address, &in) == 0) {
 121         struct hostent *ent;
 122
 123         ent = gethostbyname(address);
 124         if (ent == NULL) {
 125             goto error;
 126         }
 127
 128         memcpy(&in, ent->h_addr, sizeof(in));
 129     }
 130
 131     addr.sin_family = AF_INET;
 132     addr.sin_port = htons(port);
 133     memcpy(&addr.sin_addr.s_addr, &in, sizeof(in));
 134
 135     if (connect(s, (struct sockaddr *)&addr, sizeof(addr)) == -1) {
 136         goto error;
 137     }
 138
 139     return s;
 140 error:
 141     closesocket(s);
 142     return -1;
 143 }
 144
 145 int tcp_socket_incoming(const char *address, uint16_t port)
 146 {
 147     int s;
 148     struct in_addr in;
 149     struct sockaddr_in addr;
 150     int opt;
 151
 152     s = socket(PF_INET, SOCK_STREAM, 0);
 153     if (s == -1) {
 154         return -1;
 155     }
 156
 157     if (inet_aton(address, &in) == 0) {
 158         struct hostent *ent;
 159
 160         ent = gethostbyname(address);
 161         if (ent == NULL) {
 162             goto error;
 163         }
 164
 165         memcpy(&in, ent->h_addr, sizeof(in));
 166     }
 167
 168     addr.sin_family = AF_INET;
 169     addr.sin_port = htons(port);
 170     memcpy(&addr.sin_addr.s_addr, &in, sizeof(in));
 171
 172     opt = 1;
 173     if (setsockopt(s, SOL_SOCKET, SO_REUSEADDR,
 174                    (const void *) &opt, sizeof(opt)) == -1) {
 175         goto error;
 176     }
 177
 178     if (bind(s, (struct sockaddr *)&addr, sizeof(addr)) == -1) {
 179         goto error;
 180     }
 181
 182     if (listen(s, 128) == -1) {
 183         goto error;
 184     }
 185
 186     return s;
 187 error:
 188     closesocket(s);
 189     return -1;
 190 }
 191
 192 #ifndef _WIN32
 193 int unix_socket_incoming(const char *path)
 194 {
 195     int s;
 196     struct sockaddr_un addr;
 197
 198     s = socket(PF_UNIX, SOCK_STREAM, 0);
 199     if (s == -1) {
 200         return -1;
 201     }
 202
 203     memset(&addr, 0, sizeof(addr));
 204     addr.sun_family = AF_UNIX;
 205     pstrcpy(addr.sun_path, sizeof(addr.sun_path), path);
 206
 207     if (bind(s, (struct sockaddr *)&addr, sizeof(addr)) == -1) {
 208         goto error;
 209     }
 210
 211     if (listen(s, 128) == -1) {
 212         goto error;
 213     }
 214
 215     return s;
 216 error:
 217     closesocket(s);
 218     return -1;
 219 }
 220
 221 int unix_socket_outgoing(const char *path)
 222 {
 223     int s;
 224     struct sockaddr_un addr;
 225
 226     s = socket(PF_UNIX, SOCK_STREAM, 0);
 227     if (s == -1) {
 228         return -1;
 229     }
 230
 231     memset(&addr, 0, sizeof(addr));
 232     addr.sun_family = AF_UNIX;
 233     pstrcpy(addr.sun_path, sizeof(addr.sun_path), path);
 234
 235     if (connect(s, (struct sockaddr *)&addr, sizeof(addr)) == -1) {
 236         goto error;
 237     }
 238
 239     return s;
 240 error:
 241     closesocket(s);
 242     return -1;
 243 }
 244 #else
 245 int unix_socket_incoming(const char *path)
 246 {
 247     errno = ENOTSUP;
 248     return -1;
 249 }
 250
 251 int unix_socket_outgoing(const char *path)
 252 {
 253     errno = ENOTSUP;
 254     return -1;
 255 }
 256 #endif
 257
 258
 259 /* Basic flow
 260
 261    Server         Client
 262
 263    Negotiate
 264                   Request
 265    Response
 266                   Request
 267    Response
 268                   ...
 269    ...
 270                   Request (type == 2)
 271 */
 272
 273 int nbd_negotiate(int csock, off_t size)
 274 {
 275         char buf[8 + 8 + 8 + 128];
 276
 277         /* Negotiate
 278            [ 0 ..   7]   passwd   ("NBDMAGIC")
 279            [ 8 ..  15]   magic    (0x00420281861253)
 280            [16 ..  23]   size
 281            [24 .. 151]   reserved (0)
 282          */
 283
 284         TRACE("Beginning negotiation.");
 285         memcpy(buf, "NBDMAGIC", 8);
 286         cpu_to_be64w((uint64_t*)(buf + 8), 0x00420281861253LL);
 287         cpu_to_be64w((uint64_t*)(buf + 16), size);
 288         memset(buf + 24, 0, 128);
 289
 290         if (write_sync(csock, buf, sizeof(buf)) != sizeof(buf)) {
 291                 LOG("write failed");
 292                 errno = EINVAL;
 293                 return -1;
 294         }
 295
 296         TRACE("Negotation succeeded.");
 297
 298         return 0;
 299 }
 300
 301 int nbd_receive_negotiate(int csock, const char *name, uint32_t *flags,
 302                           off_t *size, size_t *blocksize)
 303 {
 304         char buf[256];
 305         uint64_t magic, s;
 306         uint16_t tmp;
 307
 308         TRACE("Receiving negotation.");
 309
 310         if (read_sync(csock, buf, 8) != 8) {
 311                 LOG("read failed");
 312                 errno = EINVAL;
 313                 return -1;
 314         }
 315
 316         buf[8] = '\0';
 317         if (strlen(buf) == 0) {
 318                 LOG("server connection closed");
 319                 errno = EINVAL;
 320                 return -1;
 321         }
 322
 323         TRACE("Magic is %c%c%c%c%c%c%c%c",
 324               qemu_isprint(buf[0]) ? buf[0] : '.',
 325               qemu_isprint(buf[1]) ? buf[1] : '.',
 326               qemu_isprint(buf[2]) ? buf[2] : '.',
 327               qemu_isprint(buf[3]) ? buf[3] : '.',
 328               qemu_isprint(buf[4]) ? buf[4] : '.',
 329               qemu_isprint(buf[5]) ? buf[5] : '.',
 330               qemu_isprint(buf[6]) ? buf[6] : '.',
 331               qemu_isprint(buf[7]) ? buf[7] : '.');
 332
 333         if (memcmp(buf, "NBDMAGIC", 8) != 0) {
 334                 LOG("Invalid magic received");
 335                 errno = EINVAL;
 336                 return -1;
 337         }
 338
 339         if (read_sync(csock, &magic, sizeof(magic)) != sizeof(magic)) {
 340                 LOG("read failed");
 341                 errno = EINVAL;
 342                 return -1;
 343         }
 344         magic = be64_to_cpu(magic);
 345         TRACE("Magic is 0x%" PRIx64, magic);
 346
 347         if (name) {
 348                 uint32_t reserved = 0;
 349                 uint32_t opt;
 350                 uint32_t namesize;
 351
 352                 TRACE("Checking magic (opts_magic)");
 353                 if (magic != 0x49484156454F5054LL) {
 354                         LOG("Bad magic received");
 355                         errno = EINVAL;
 356                         return -1;
 357                 }
 358                 if (read_sync(csock, &tmp, sizeof(tmp)) != sizeof(tmp)) {
 359                         LOG("flags read failed");
 360                         errno = EINVAL;
 361                         return -1;
 362                 }
 363                 *flags = be16_to_cpu(tmp) << 16;
 364                 /* reserved for future use */
 365                 if (write_sync(csock, &reserved, sizeof(reserved)) !=
 366                     sizeof(reserved)) {
 367                         LOG("write failed (reserved)");
 368                         errno = EINVAL;
 369                         return -1;
 370                 }
 371                 /* write the export name */
 372                 magic = cpu_to_be64(magic);
 373                 if (write_sync(csock, &magic, sizeof(magic)) != sizeof(magic)) {
 374                         LOG("write failed (magic)");
 375                         errno = EINVAL;
 376                         return -1;
 377                 }
 378                 opt = cpu_to_be32(NBD_OPT_EXPORT_NAME);
 379                 if (write_sync(csock, &opt, sizeof(opt)) != sizeof(opt)) {
 380                         LOG("write failed (opt)");
 381                         errno = EINVAL;
 382                         return -1;
 383                 }
 384                 namesize = cpu_to_be32(strlen(name));
 385                 if (write_sync(csock, &namesize, sizeof(namesize)) !=
 386                     sizeof(namesize)) {
 387                         LOG("write failed (namesize)");
 388                         errno = EINVAL;
 389                         return -1;
 390                 }
 391                 if (write_sync(csock, (char*)name, strlen(name)) != strlen(name)) {
 392                         LOG("write failed (name)");
 393                         errno = EINVAL;
 394                         return -1;
 395                 }
 396         } else {
 397                 TRACE("Checking magic (cli_magic)");
 398
 399                 if (magic != 0x00420281861253LL) {
 400                         LOG("Bad magic received");
 401                         errno = EINVAL;
 402                         return -1;
 403                 }
 404         }
 405
 406         if (read_sync(csock, &s, sizeof(s)) != sizeof(s)) {
 407                 LOG("read failed");
 408                 errno = EINVAL;
 409                 return -1;
 410         }
 411         *size = be64_to_cpu(s);
 412         *blocksize = 1024;
 413         TRACE("Size is %" PRIu64, *size);
 414
 415         if (!name) {
 416                 if (read_sync(csock, flags, sizeof(*flags)) != sizeof(*flags)) {
 417                         LOG("read failed (flags)");
 418                         errno = EINVAL;
 419                         return -1;
 420                 }
 421                 *flags = be32_to_cpup(flags);
 422         } else {
 423                 if (read_sync(csock, &tmp, sizeof(tmp)) != sizeof(tmp)) {
 424                         LOG("read failed (tmp)");
 425                         errno = EINVAL;
 426                         return -1;
 427                 }
 428                 *flags |= be32_to_cpu(tmp);
 429         }
 430         if (read_sync(csock, &buf, 124) != 124) {
 431                 LOG("read failed (buf)");
 432                 errno = EINVAL;
 433                 return -1;
 434         }
 435         return 0;
 436 }
 437
 438 #ifndef _WIN32
 439 int nbd_init(int fd, int csock, off_t size, size_t blocksize)
 440 {
 441         TRACE("Setting block size to %lu", (unsigned long)blocksize);
 442
 443         if (ioctl(fd, NBD_SET_BLKSIZE, blocksize) == -1) {
 444                 int serrno = errno;
 445                 LOG("Failed setting NBD block size");
 446                 errno = serrno;
 447                 return -1;
 448         }
 449
 450         TRACE("Setting size to %zd block(s)", (size_t)(size / blocksize));
 451
 452         if (ioctl(fd, NBD_SET_SIZE_BLOCKS, size / blocksize) == -1) {
 453                 int serrno = errno;
 454                 LOG("Failed setting size (in blocks)");
 455                 errno = serrno;
 456                 return -1;
 457         }
 458
 459         TRACE("Clearing NBD socket");
 460
 461         if (ioctl(fd, NBD_CLEAR_SOCK) == -1) {
 462                 int serrno = errno;
 463                 LOG("Failed clearing NBD socket");
 464                 errno = serrno;
 465                 return -1;
 466         }
 467
 468         TRACE("Setting NBD socket");
 469
 470         if (ioctl(fd, NBD_SET_SOCK, csock) == -1) {
 471                 int serrno = errno;
 472                 LOG("Failed to set NBD socket");
 473                 errno = serrno;
 474                 return -1;
 475         }
 476
 477         TRACE("Negotiation ended");
 478
 479         return 0;
 480 }
 481
 482 int nbd_disconnect(int fd)
 483 {
 484         ioctl(fd, NBD_CLEAR_QUE);
 485         ioctl(fd, NBD_DISCONNECT);
 486         ioctl(fd, NBD_CLEAR_SOCK);
 487         return 0;
 488 }
 489
 490 int nbd_client(int fd, int csock)
 491 {
 492         int ret;
 493         int serrno;
 494
 495         TRACE("Doing NBD loop");
 496
 497         ret = ioctl(fd, NBD_DO_IT);
 498         serrno = errno;
 499
 500         TRACE("NBD loop returned %d: %s", ret, strerror(serrno));
 501
 502         TRACE("Clearing NBD queue");
 503         ioctl(fd, NBD_CLEAR_QUE);
 504
 505         TRACE("Clearing NBD socket");
 506         ioctl(fd, NBD_CLEAR_SOCK);
 507
 508         errno = serrno;
 509         return ret;
 510 }
 511 #else
 512 int nbd_init(int fd, int csock, off_t size, size_t blocksize)
 513 {
 514     errno = ENOTSUP;
 515     return -1;
 516 }
 517
 518 int nbd_disconnect(int fd)
 519 {
 520     errno = ENOTSUP;
 521     return -1;
 522 }
 523
 524 int nbd_client(int fd, int csock)
 525 {
 526     errno = ENOTSUP;
 527     return -1;
 528 }
 529 #endif
 530
 531 int nbd_send_request(int csock, struct nbd_request *request)
 532 {
 533         uint8_t buf[4 + 4 + 8 + 8 + 4];
 534
 535         cpu_to_be32w((uint32_t*)buf, NBD_REQUEST_MAGIC);
 536         cpu_to_be32w((uint32_t*)(buf + 4), request->type);
 537         cpu_to_be64w((uint64_t*)(buf + 8), request->handle);
 538         cpu_to_be64w((uint64_t*)(buf + 16), request->from);
 539         cpu_to_be32w((uint32_t*)(buf + 24), request->len);
 540
 541         TRACE("Sending request to client");
 542
 543         if (write_sync(csock, buf, sizeof(buf)) != sizeof(buf)) {
 544                 LOG("writing to socket failed");
 545                 errno = EINVAL;
 546                 return -1;
 547         }
 548         return 0;
 549 }
 550
 551
 552 static int nbd_receive_request(int csock, struct nbd_request *request)
 553 {
 554         uint8_t buf[4 + 4 + 8 + 8 + 4];
 555         uint32_t magic;
 556
 557         if (read_sync(csock, buf, sizeof(buf)) != sizeof(buf)) {
 558                 LOG("read failed");
 559                 errno = EINVAL;
 560                 return -1;
 561         }
 562
 563         /* Request
 564            [ 0 ..  3]   magic   (NBD_REQUEST_MAGIC)
 565            [ 4 ..  7]   type    (0 == READ, 1 == WRITE)
 566            [ 8 .. 15]   handle
 567            [16 .. 23]   from
 568            [24 .. 27]   len
 569          */
 570
 571         magic = be32_to_cpup((uint32_t*)buf);
 572         request->type  = be32_to_cpup((uint32_t*)(buf + 4));
 573         request->handle = be64_to_cpup((uint64_t*)(buf + 8));
 574         request->from  = be64_to_cpup((uint64_t*)(buf + 16));
 575         request->len   = be32_to_cpup((uint32_t*)(buf + 24));
 576
 577         TRACE("Got request: "
 578               "{ magic = 0x%x, .type = %d, from = %" PRIu64" , len = %u }",
 579               magic, request->type, request->from, request->len);
 580
 581         if (magic != NBD_REQUEST_MAGIC) {
 582                 LOG("invalid magic (got 0x%x)", magic);
 583                 errno = EINVAL;
 584                 return -1;
 585         }
 586         return 0;
 587 }
 588
 589 int nbd_receive_reply(int csock, struct nbd_reply *reply)
 590 {
 591         uint8_t buf[4 + 4 + 8];
 592         uint32_t magic;
 593
 594         memset(buf, 0xAA, sizeof(buf));
 595
 596         if (read_sync(csock, buf, sizeof(buf)) != sizeof(buf)) {
 597                 LOG("read failed");
 598                 errno = EINVAL;
 599                 return -1;
 600         }
 601
 602         /* Reply
 603            [ 0 ..  3]    magic   (NBD_REPLY_MAGIC)
 604            [ 4 ..  7]    error   (0 == no error)
 605            [ 7 .. 15]    handle
 606          */
 607
 608         magic = be32_to_cpup((uint32_t*)buf);
 609         reply->error  = be32_to_cpup((uint32_t*)(buf + 4));
 610         reply->handle = be64_to_cpup((uint64_t*)(buf + 8));
 611
 612         TRACE("Got reply: "
 613               "{ magic = 0x%x, .error = %d, handle = %" PRIu64" }",
 614               magic, reply->error, reply->handle);
 615
 616         if (magic != NBD_REPLY_MAGIC) {
 617                 LOG("invalid magic (got 0x%x)", magic);
 618                 errno = EINVAL;
 619                 return -1;
 620         }
 621         return 0;
 622 }
 623
 624 static int nbd_send_reply(int csock, struct nbd_reply *reply)
 625 {
 626         uint8_t buf[4 + 4 + 8];
 627
 628         /* Reply
 629            [ 0 ..  3]    magic   (NBD_REPLY_MAGIC)
 630            [ 4 ..  7]    error   (0 == no error)
 631            [ 7 .. 15]    handle
 632          */
 633         cpu_to_be32w((uint32_t*)buf, NBD_REPLY_MAGIC);
 634         cpu_to_be32w((uint32_t*)(buf + 4), reply->error);
 635         cpu_to_be64w((uint64_t*)(buf + 8), reply->handle);
 636
 637         TRACE("Sending response to client");
 638
 639         if (write_sync(csock, buf, sizeof(buf)) != sizeof(buf)) {
 640                 LOG("writing to socket failed");
 641                 errno = EINVAL;
 642                 return -1;
 643         }
 644         return 0;
 645 }
 646
 647 int nbd_trip(BlockDriverState *bs, int csock, off_t size, uint64_t dev_offset,
 648              off_t *offset, bool readonly, uint8_t *data, int data_size)
 649 {
 650         struct nbd_request request;
 651         struct nbd_reply reply;
 652
 653         TRACE("Reading request.");
 654
 655         if (nbd_receive_request(csock, &request) == -1)
 656                 return -1;
 657
 658         if (request.len > data_size) {
 659                 LOG("len (%u) is larger than max len (%u)",
 660                     request.len, data_size);
 661                 errno = EINVAL;
 662                 return -1;
 663         }
 664
 665         if ((request.from + request.len) < request.from) {
 666                 LOG("integer overflow detected! "
 667                     "you're probably being attacked");
 668                 errno = EINVAL;
 669                 return -1;
 670         }
 671
 672         if ((request.from + request.len) > size) {
 673                 LOG("From: %" PRIu64 ", Len: %u, Size: %" PRIu64
 674                     ", Offset: %" PRIu64 "\n",
 675                     request.from, request.len, (uint64_t)size, dev_offset);
 676                 LOG("requested operation past EOF--bad client?");
 677                 errno = EINVAL;
 678                 return -1;
 679         }
 680
 681         TRACE("Decoding type");
 682
 683         reply.handle = request.handle;
 684         reply.error = 0;
 685
 686         switch (request.type) {
 687         case NBD_CMD_READ:
 688                 TRACE("Request type is READ");
 689
 690                 if (bdrv_read(bs, (request.from + dev_offset) / 512, data,
 691                               request.len / 512) == -1) {
 692                         LOG("reading from file failed");
 693                         errno = EINVAL;
 694                         return -1;
 695                 }
 696                 *offset += request.len;
 697
 698                 TRACE("Read %u byte(s)", request.len);
 699
 700                 if (nbd_send_reply(csock, &reply) == -1)
 701                         return -1;
 702
 703                 TRACE("Sending data to client");
 704
 705                 if (write_sync(csock, data, request.len) != request.len) {
 706                         LOG("writing to socket failed");
 707                         errno = EINVAL;
 708                         return -1;
 709                 }
 710                 break;
 711         case NBD_CMD_WRITE:
 712                 TRACE("Request type is WRITE");
 713
 714                 TRACE("Reading %u byte(s)", request.len);
 715
 716                 if (read_sync(csock, data, request.len) != request.len) {
 717                         LOG("reading from socket failed");
 718                         errno = EINVAL;
 719                         return -1;
 720                 }
 721
 722                 if (readonly) {
 723                         TRACE("Server is read-only, return error");
 724                         reply.error = 1;
 725                 } else {
 726                         TRACE("Writing to device");
 727
 728                         if (bdrv_write(bs, (request.from + dev_offset) / 512,
 729                                        data, request.len / 512) == -1) {
 730                                 LOG("writing to file failed");
 731                                 errno = EINVAL;
 732                                 return -1;
 733                         }
 734
 735                         *offset += request.len;
 736                 }
 737
 738                 if (nbd_send_reply(csock, &reply) == -1)
 739                         return -1;
 740                 break;
 741         case NBD_CMD_DISC:
 742                 TRACE("Request type is DISCONNECT");
 743                 errno = 0;
 744                 return 1;
 745         default:
 746                 LOG("invalid request type (%u) received", request.type);
 747                 errno = EINVAL;
 748                 return -1;
 749         }
 750
 751         TRACE("Request/Reply complete");
 752
 753         return 0;
 754 }