backend/dnssd.c

   1 /*
   2  * "$Id: dnssd.c 12660 2015-05-22 19:09:57Z msweet $"
   3  *
   4  * DNS-SD discovery backend for CUPS.
   5  *
   6  * Copyright 2008-2015 by Apple Inc.
   7  *
   8  * These coded instructions, statements, and computer programs are the
   9  * property of Apple Inc. and are protected by Federal copyright
  10  * law.  Distribution and use rights are outlined in the file "LICENSE.txt"
  11  * "LICENSE" which should have been included with this file.  If this
  12  * file is missing or damaged, see the license at "http://www.cups.org/".
  13  *
  14  * This file is subject to the Apple OS-Developed Software exception.
  15  */
  16
  17 /*
  18  * Include necessary headers.
  19  */
  20
  21 #include "backend-private.h"
  22 #include <cups/array.h>
  23 #ifdef HAVE_DNSSD
  24 #  include <dns_sd.h>
  25 #endif /* HAVE_DNSSD */
  26 #ifdef HAVE_AVAHI
  27 #  include <avahi-client/client.h>
  28 #  include <avahi-client/lookup.h>
  29 #  include <avahi-common/simple-watch.h>
  30 #  include <avahi-common/domain.h>
  31 #  include <avahi-common/error.h>
  32 #  include <avahi-common/malloc.h>
  33 #define kDNSServiceMaxDomainName AVAHI_DOMAIN_NAME_MAX
  34 #endif /* HAVE_AVAHI */
  35
  36
  37 /*
  38  * Device structure...
  39  */
  40
  41 typedef enum
  42 {
  43   CUPS_DEVICE_PRINTER = 0,              /* lpd://... */
  44   CUPS_DEVICE_IPPS,                     /* ipps://... */
  45   CUPS_DEVICE_IPP,                      /* ipp://... */
  46   CUPS_DEVICE_FAX_IPP,                  /* ipp://... */
  47   CUPS_DEVICE_PDL_DATASTREAM,           /* socket://... */
  48   CUPS_DEVICE_RIOUSBPRINT               /* riousbprint://... */
  49 } cups_devtype_t;
  50
  51
  52 typedef struct
  53 {
  54 #ifdef HAVE_DNSSD
  55   DNSServiceRef ref;                    /* Service reference for query */
  56 #endif /* HAVE_DNSSD */
  57 #ifdef HAVE_AVAHI
  58   AvahiRecordBrowser *ref;              /* Browser for query */
  59 #endif /* HAVE_AVAHI */
  60   char          *name,                  /* Service name */
  61                 *domain,                /* Domain name */
  62                 *fullName,              /* Full name */
  63                 *make_and_model,        /* Make and model from TXT record */
  64                 *device_id,             /* 1284 device ID from TXT record */
  65                 *uuid;                  /* UUID from TXT record */
  66   cups_devtype_t type;                  /* Device registration type */
  67   int           priority,               /* Priority associated with type */
  68                 cups_shared,            /* CUPS shared printer? */
  69                 sent;                   /* Did we list the device? */
  70 } cups_device_t;
  71
  72
  73 /*
  74  * Local globals...
  75  */
  76
  77 static int              job_canceled = 0;
  78                                         /* Set to 1 on SIGTERM */
  79 #ifdef HAVE_AVAHI
  80 static AvahiSimplePoll  *simple_poll = NULL;
  81                                         /* Poll information */
  82 static int              got_data = 0;   /* Got data from poll? */
  83 static int              browsers = 0;   /* Number of running browsers */
  84 #endif /* HAVE_AVAHI */
  85
  86
  87 /*
  88  * Local functions...
  89  */
  90
  91 #ifdef HAVE_DNSSD
  92 static void             browse_callback(DNSServiceRef sdRef,
  93                                         DNSServiceFlags flags,
  94                                         uint32_t interfaceIndex,
  95                                         DNSServiceErrorType errorCode,
  96                                         const char *serviceName,
  97                                         const char *regtype,
  98                                         const char *replyDomain, void *context)
  99                                         __attribute__((nonnull(1,5,6,7,8)));
 100 static void             browse_local_callback(DNSServiceRef sdRef,
 101                                               DNSServiceFlags flags,
 102                                               uint32_t interfaceIndex,
 103                                               DNSServiceErrorType errorCode,
 104                                               const char *serviceName,
 105                                               const char *regtype,
 106                                               const char *replyDomain,
 107                                               void *context)
 108                                               __attribute__((nonnull(1,5,6,7,8)));
 109 #endif /* HAVE_DNSSD */
 110 #ifdef HAVE_AVAHI
 111 static void             browse_callback(AvahiServiceBrowser *browser,
 112                                         AvahiIfIndex interface,
 113                                         AvahiProtocol protocol,
 114                                         AvahiBrowserEvent event,
 115                                         const char *serviceName,
 116                                         const char *regtype,
 117                                         const char *replyDomain,
 118                                         AvahiLookupResultFlags flags,
 119                                         void *context);
 120 static void             client_callback(AvahiClient *client,
 121                                         AvahiClientState state,
 122                                         void *context);
 123 #endif /* HAVE_AVAHI */
 124
 125 static int              compare_devices(cups_device_t *a, cups_device_t *b);
 126 static void             exec_backend(char **argv) __attribute__((noreturn));
 127 static cups_device_t    *get_device(cups_array_t *devices,
 128                                     const char *serviceName,
 129                                     const char *regtype,
 130                                     const char *replyDomain)
 131                                     __attribute__((nonnull(1,2,3,4)));
 132 #ifdef HAVE_DNSSD
 133 static void             query_callback(DNSServiceRef sdRef,
 134                                        DNSServiceFlags flags,
 135                                        uint32_t interfaceIndex,
 136                                        DNSServiceErrorType errorCode,
 137                                        const char *fullName, uint16_t rrtype,
 138                                        uint16_t rrclass, uint16_t rdlen,
 139                                        const void *rdata, uint32_t ttl,
 140                                        void *context)
 141                                        __attribute__((nonnull(1,5,9,11)));
 142 #elif defined(HAVE_AVAHI)
 143 static int              poll_callback(struct pollfd *pollfds,
 144                                       unsigned int num_pollfds, int timeout,
 145                                       void *context);
 146 static void             query_callback(AvahiRecordBrowser *browser,
 147                                        AvahiIfIndex interface,
 148                                        AvahiProtocol protocol,
 149                                        AvahiBrowserEvent event,
 150                                        const char *name, uint16_t rrclass,
 151                                        uint16_t rrtype, const void *rdata,
 152                                        size_t rdlen,
 153                                        AvahiLookupResultFlags flags,
 154                                        void *context);
 155 #endif /* HAVE_DNSSD */
 156 static void             sigterm_handler(int sig);
 157 static void             unquote(char *dst, const char *src, size_t dstsize)
 158                             __attribute__((nonnull(1,2)));
 159
 160
 161 /*
 162  * 'main()' - Browse for printers.
 163  */
 164
 165 int                                     /* O - Exit status */
 166 main(int  argc,                         /* I - Number of command-line args */
 167      char *argv[])                      /* I - Command-line arguments */
 168 {
 169   const char    *name;                  /* Backend name */
 170   cups_array_t  *devices;               /* Device array */
 171   cups_device_t *device;                /* Current device */
 172   char          uriName[1024];          /* Unquoted fullName for URI */
 173 #ifdef HAVE_DNSSD
 174   int           fd;                     /* Main file descriptor */
 175   fd_set        input;                  /* Input set for select() */
 176   struct timeval timeout;               /* Timeout for select() */
 177   DNSServiceRef main_ref,               /* Main service reference */
 178                 fax_ipp_ref,            /* IPP fax service reference */
 179                 ipp_ref,                /* IPP service reference */
 180                 ipp_tls_ref,            /* IPP w/TLS service reference */
 181                 ipps_ref,               /* IPP service reference */
 182                 local_fax_ipp_ref,      /* Local IPP fax service reference */
 183                 local_ipp_ref,          /* Local IPP service reference */
 184                 local_ipp_tls_ref,      /* Local IPP w/TLS service reference */
 185                 local_ipps_ref,         /* Local IPP service reference */
 186                 local_printer_ref,      /* Local LPD service reference */
 187                 pdl_datastream_ref,     /* AppSocket service reference */
 188                 printer_ref,            /* LPD service reference */
 189                 riousbprint_ref;        /* Remote IO service reference */
 190 #endif /* HAVE_DNSSD */
 191 #ifdef HAVE_AVAHI
 192   AvahiClient   *client;                /* Client information */
 193   int           error;                  /* Error code, if any */
 194 #endif /* HAVE_AVAHI */
 195 #if defined(HAVE_SIGACTION) && !defined(HAVE_SIGSET)
 196   struct sigaction action;              /* Actions for POSIX signals */
 197 #endif /* HAVE_SIGACTION && !HAVE_SIGSET */
 198
 199
 200  /*
 201   * Don't buffer stderr, and catch SIGTERM...
 202   */
 203
 204   setbuf(stderr, NULL);
 205
 206 #ifdef HAVE_SIGSET /* Use System V signals over POSIX to avoid bugs */
 207   sigset(SIGTERM, sigterm_handler);
 208 #elif defined(HAVE_SIGACTION)
 209   memset(&action, 0, sizeof(action));
 210
 211   sigemptyset(&action.sa_mask);
 212   action.sa_handler = sigterm_handler;
 213   sigaction(SIGTERM, &action, NULL);
 214 #else
 215   signal(SIGTERM, sigterm_handler);
 216 #endif /* HAVE_SIGSET */
 217
 218  /*
 219   * Check command-line...
 220   */
 221
 222   if (argc >= 6)
 223     exec_backend(argv);
 224   else if (argc != 1)
 225   {
 226     _cupsLangPrintf(stderr,
 227                     _("Usage: %s job-id user title copies options [file]"),
 228                     argv[0]);
 229     return (1);
 230   }
 231
 232  /*
 233   * Only do discovery when run as "dnssd"...
 234   */
 235
 236   if ((name = strrchr(argv[0], '/')) != NULL)
 237     name ++;
 238   else
 239     name = argv[0];
 240
 241   if (strcmp(name, "dnssd"))
 242     return (0);
 243
 244  /*
 245   * Create an array to track devices...
 246   */
 247
 248   devices = cupsArrayNew((cups_array_func_t)compare_devices, NULL);
 249
 250  /*
 251   * Browse for different kinds of printers...
 252   */
 253
 254 #ifdef HAVE_DNSSD
 255   if (DNSServiceCreateConnection(&main_ref) != kDNSServiceErr_NoError)
 256   {
 257     perror("ERROR: Unable to create service connection");
 258     return (1);
 259   }
 260
 261   fd = DNSServiceRefSockFD(main_ref);
 262
 263   fax_ipp_ref = main_ref;
 264   DNSServiceBrowse(&fax_ipp_ref, kDNSServiceFlagsShareConnection, 0,
 265                    "_fax-ipp._tcp", NULL, browse_callback, devices);
 266
 267   ipp_ref = main_ref;
 268   DNSServiceBrowse(&ipp_ref, kDNSServiceFlagsShareConnection, 0,
 269                    "_ipp._tcp", NULL, browse_callback, devices);
 270
 271   ipp_tls_ref = main_ref;
 272   DNSServiceBrowse(&ipp_tls_ref, kDNSServiceFlagsShareConnection, 0,
 273                    "_ipp-tls._tcp", NULL, browse_callback, devices);
 274
 275   ipps_ref = main_ref;
 276   DNSServiceBrowse(&ipps_ref, kDNSServiceFlagsShareConnection, 0,
 277                    "_ipps._tcp", NULL, browse_callback, devices);
 278
 279   local_fax_ipp_ref = main_ref;
 280   DNSServiceBrowse(&local_fax_ipp_ref, kDNSServiceFlagsShareConnection,
 281                    kDNSServiceInterfaceIndexLocalOnly,
 282                    "_fax-ipp._tcp", NULL, browse_local_callback, devices);
 283
 284   local_ipp_ref = main_ref;
 285   DNSServiceBrowse(&local_ipp_ref, kDNSServiceFlagsShareConnection,
 286                    kDNSServiceInterfaceIndexLocalOnly,
 287                    "_ipp._tcp", NULL, browse_local_callback, devices);
 288
 289   local_ipp_tls_ref = main_ref;
 290   DNSServiceBrowse(&local_ipp_tls_ref, kDNSServiceFlagsShareConnection,
 291                    kDNSServiceInterfaceIndexLocalOnly,
 292                    "_ipp-tls._tcp", NULL, browse_local_callback, devices);
 293
 294   local_ipps_ref = main_ref;
 295   DNSServiceBrowse(&local_ipps_ref, kDNSServiceFlagsShareConnection,
 296                    kDNSServiceInterfaceIndexLocalOnly,
 297                    "_ipps._tcp", NULL, browse_local_callback, devices);
 298
 299   local_printer_ref = main_ref;
 300   DNSServiceBrowse(&local_printer_ref, kDNSServiceFlagsShareConnection,
 301                    kDNSServiceInterfaceIndexLocalOnly,
 302                    "_printer._tcp", NULL, browse_local_callback, devices);
 303
 304   pdl_datastream_ref = main_ref;
 305   DNSServiceBrowse(&pdl_datastream_ref, kDNSServiceFlagsShareConnection, 0,
 306                    "_pdl-datastream._tcp", NULL, browse_callback, devices);
 307
 308   printer_ref = main_ref;
 309   DNSServiceBrowse(&printer_ref, kDNSServiceFlagsShareConnection, 0,
 310                    "_printer._tcp", NULL, browse_callback, devices);
 311
 312   riousbprint_ref = main_ref;
 313   DNSServiceBrowse(&riousbprint_ref, kDNSServiceFlagsShareConnection, 0,
 314                    "_riousbprint._tcp", NULL, browse_callback, devices);
 315 #endif /* HAVE_DNSSD */
 316
 317 #ifdef HAVE_AVAHI
 318   if ((simple_poll = avahi_simple_poll_new()) == NULL)
 319   {
 320     fputs("DEBUG: Unable to create Avahi simple poll object.\n", stderr);
 321     return (0);
 322   }
 323
 324   avahi_simple_poll_set_func(simple_poll, poll_callback, NULL);
 325
 326   client = avahi_client_new(avahi_simple_poll_get(simple_poll),
 327                             0, client_callback, simple_poll, &error);
 328   if (!client)
 329   {
 330     fputs("DEBUG: Unable to create Avahi client.\n", stderr);
 331     return (0);
 332   }
 333
 334   browsers = 6;
 335   avahi_service_browser_new(client, AVAHI_IF_UNSPEC,
 336                             AVAHI_PROTO_UNSPEC,
 337                             "_fax-ipp._tcp", NULL, 0,
 338                             browse_callback, devices);
 339   avahi_service_browser_new(client, AVAHI_IF_UNSPEC,
 340                             AVAHI_PROTO_UNSPEC,
 341                             "_ipp._tcp", NULL, 0,
 342                             browse_callback, devices);
 343   avahi_service_browser_new(client, AVAHI_IF_UNSPEC,
 344                             AVAHI_PROTO_UNSPEC,
 345                             "_ipp-tls._tcp", NULL, 0,
 346                             browse_callback, devices);
 347   avahi_service_browser_new(client, AVAHI_IF_UNSPEC,
 348                             AVAHI_PROTO_UNSPEC,
 349                             "_ipps._tcp", NULL, 0,
 350                             browse_callback, devices);
 351   avahi_service_browser_new(client, AVAHI_IF_UNSPEC,
 352                             AVAHI_PROTO_UNSPEC,
 353                             "_pdl-datastream._tcp",
 354                             NULL, 0,
 355                             browse_callback,
 356                             devices);
 357   avahi_service_browser_new(client, AVAHI_IF_UNSPEC,
 358                             AVAHI_PROTO_UNSPEC,
 359                             "_printer._tcp", NULL, 0,
 360                             browse_callback, devices);
 361 #endif /* HAVE_AVAHI */
 362
 363  /*
 364   * Loop until we are killed...
 365   */
 366
 367   while (!job_canceled)
 368   {
 369     int announce = 0;                   /* Announce printers? */
 370
 371 #ifdef HAVE_DNSSD
 372     FD_ZERO(&input);
 373     FD_SET(fd, &input);
 374
 375     timeout.tv_sec  = 0;
 376     timeout.tv_usec = 500000;
 377
 378     if (select(fd + 1, &input, NULL, NULL, &timeout) < 0)
 379       continue;
 380
 381     if (FD_ISSET(fd, &input))
 382     {
 383      /*
 384       * Process results of our browsing...
 385       */
 386
 387       DNSServiceProcessResult(main_ref);
 388     }
 389     else
 390       announce = 1;
 391
 392 #elif defined(HAVE_AVAHI)
 393     got_data = 0;
 394
 395     if ((error = avahi_simple_poll_iterate(simple_poll, 500)) > 0)
 396     {
 397      /*
 398       * We've been told to exit the loop.  Perhaps the connection to
 399       * Avahi failed.
 400       */
 401
 402       break;
 403     }
 404
 405     if (!got_data)
 406       announce = 1;
 407 #endif /* HAVE_DNSSD */
 408
 409 /*    fprintf(stderr, "DEBUG: announce=%d\n", announce);*/
 410
 411     if (announce)
 412     {
 413      /*
 414       * Announce any devices we've found...
 415       */
 416
 417 #ifdef HAVE_DNSSD
 418       DNSServiceErrorType status;       /* DNS query status */
 419 #endif /* HAVE_DNSSD */
 420       cups_device_t *best;              /* Best matching device */
 421       char      device_uri[1024];       /* Device URI */
 422       int       count;                  /* Number of queries */
 423       int       sent;                   /* Number of sent */
 424
 425       for (device = (cups_device_t *)cupsArrayFirst(devices),
 426                best = NULL, count = 0, sent = 0;
 427            device;
 428            device = (cups_device_t *)cupsArrayNext(devices))
 429       {
 430         if (device->sent)
 431           sent ++;
 432
 433         if (device->ref)
 434           count ++;
 435
 436         if (!device->ref && !device->sent)
 437         {
 438          /*
 439           * Found the device, now get the TXT record(s) for it...
 440           */
 441
 442           if (count < 50)
 443           {
 444             fprintf(stderr, "DEBUG: Querying \"%s\"...\n", device->fullName);
 445
 446 #ifdef HAVE_DNSSD
 447             device->ref = main_ref;
 448
 449             status = DNSServiceQueryRecord(&(device->ref),
 450                                            kDNSServiceFlagsShareConnection,
 451                                            0, device->fullName,
 452                                            kDNSServiceType_TXT,
 453                                            kDNSServiceClass_IN, query_callback,
 454                                            device);
 455             if (status != kDNSServiceErr_NoError)
 456               fprintf(stderr,
 457                       "ERROR: Unable to query \"%s\" for TXT records: %d\n",
 458                       device->fullName, status);
 459                                         /* Users never see this */
 460             else
 461               count ++;
 462
 463 #else
 464             if ((device->ref = avahi_record_browser_new(client, AVAHI_IF_UNSPEC,
 465                                                         AVAHI_PROTO_UNSPEC,
 466                                                         device->fullName,
 467                                                         AVAHI_DNS_CLASS_IN,
 468                                                         AVAHI_DNS_TYPE_TXT,
 469                                                         0,
 470                                                         query_callback,
 471                                                         device)) == NULL)
 472               fprintf(stderr,
 473                       "ERROR: Unable to query \"%s\" for TXT records: %s\n",
 474                       device->fullName,
 475                       avahi_strerror(avahi_client_errno(client)));
 476                                         /* Users never see this */
 477             else
 478               count ++;
 479 #endif /* HAVE_AVAHI */
 480           }
 481         }
 482         else if (!device->sent)
 483         {
 484 #ifdef HAVE_DNSSD
 485          /*
 486           * Got the TXT records, now report the device...
 487           */
 488
 489           DNSServiceRefDeallocate(device->ref);
 490 #else
 491           avahi_record_browser_free(device->ref);
 492 #endif /* HAVE_DNSSD */
 493
 494           device->ref = NULL;
 495
 496           if (!best)
 497             best = device;
 498           else if (_cups_strcasecmp(best->name, device->name) ||
 499                    _cups_strcasecmp(best->domain, device->domain))
 500           {
 501             unquote(uriName, best->fullName, sizeof(uriName));
 502
 503             if (best->uuid)
 504               httpAssembleURIf(HTTP_URI_CODING_ALL, device_uri,
 505                                sizeof(device_uri), "dnssd", NULL, uriName, 0,
 506                                best->cups_shared ? "/cups?uuid=%s" : "/?uuid=%s",
 507                                best->uuid);
 508             else
 509               httpAssembleURI(HTTP_URI_CODING_ALL, device_uri,
 510                               sizeof(device_uri), "dnssd", NULL, uriName, 0,
 511                               best->cups_shared ? "/cups" : "/");
 512
 513             cupsBackendReport("network", device_uri, best->make_and_model,
 514                               best->name, best->device_id, NULL);
 515             best->sent = 1;
 516             best       = device;
 517
 518             sent ++;
 519           }
 520           else if (best->priority > device->priority ||
 521                    (best->priority == device->priority &&
 522                     best->type < device->type))
 523           {
 524             best->sent = 1;
 525             best       = device;
 526
 527             sent ++;
 528           }
 529           else
 530           {
 531             device->sent = 1;
 532
 533             sent ++;
 534           }
 535         }
 536       }
 537
 538       if (best)
 539       {
 540         unquote(uriName, best->fullName, sizeof(uriName));
 541
 542         if (best->uuid)
 543           httpAssembleURIf(HTTP_URI_CODING_ALL, device_uri,
 544                            sizeof(device_uri), "dnssd", NULL, uriName, 0,
 545                            best->cups_shared ? "/cups?uuid=%s" : "/?uuid=%s",
 546                            best->uuid);
 547         else
 548           httpAssembleURI(HTTP_URI_CODING_ALL, device_uri,
 549                           sizeof(device_uri), "dnssd", NULL, uriName, 0,
 550                           best->cups_shared ? "/cups" : "/");
 551
 552         cupsBackendReport("network", device_uri, best->make_and_model,
 553                           best->name, best->device_id, NULL);
 554         best->sent = 1;
 555         sent ++;
 556       }
 557
 558       fprintf(stderr, "DEBUG: sent=%d, count=%d\n", sent, count);
 559
 560 #ifdef HAVE_AVAHI
 561       if (sent == cupsArrayCount(devices) && browsers == 0)
 562 #else
 563       if (sent == cupsArrayCount(devices))
 564 #endif /* HAVE_AVAHI */
 565         break;
 566     }
 567   }
 568
 569   return (CUPS_BACKEND_OK);
 570 }
 571
 572
 573 #ifdef HAVE_DNSSD
 574 /*
 575  * 'browse_callback()' - Browse devices.
 576  */
 577
 578 static void
 579 browse_callback(
 580     DNSServiceRef       sdRef,          /* I - Service reference */
 581     DNSServiceFlags     flags,          /* I - Option flags */
 582     uint32_t            interfaceIndex, /* I - Interface number */
 583     DNSServiceErrorType errorCode,      /* I - Error, if any */
 584     const char          *serviceName,   /* I - Name of service/device */
 585     const char          *regtype,       /* I - Type of service */
 586     const char          *replyDomain,   /* I - Service domain */
 587     void                *context)       /* I - Devices array */
 588 {
 589   fprintf(stderr, "DEBUG2: browse_callback(sdRef=%p, flags=%x, "
 590                   "interfaceIndex=%d, errorCode=%d, serviceName=\"%s\", "
 591                   "regtype=\"%s\", replyDomain=\"%s\", context=%p)\n",
 592           sdRef, flags, interfaceIndex, errorCode,
 593           serviceName, regtype, replyDomain, context);
 594
 595  /*
 596   * Only process "add" data...
 597   */
 598
 599   if (errorCode != kDNSServiceErr_NoError || !(flags & kDNSServiceFlagsAdd))
 600     return;
 601
 602  /*
 603   * Get the device...
 604   */
 605
 606   get_device((cups_array_t *)context, serviceName, regtype, replyDomain);
 607 }
 608
 609
 610 /*
 611  * 'browse_local_callback()' - Browse local devices.
 612  */
 613
 614 static void
 615 browse_local_callback(
 616     DNSServiceRef       sdRef,          /* I - Service reference */
 617     DNSServiceFlags     flags,          /* I - Option flags */
 618     uint32_t            interfaceIndex, /* I - Interface number */
 619     DNSServiceErrorType errorCode,      /* I - Error, if any */
 620     const char          *serviceName,   /* I - Name of service/device */
 621     const char          *regtype,       /* I - Type of service */
 622     const char          *replyDomain,   /* I - Service domain */
 623     void                *context)       /* I - Devices array */
 624 {
 625   cups_device_t *device;                /* Device */
 626
 627
 628   fprintf(stderr, "DEBUG2: browse_local_callback(sdRef=%p, flags=%x, "
 629                   "interfaceIndex=%d, errorCode=%d, serviceName=\"%s\", "
 630                   "regtype=\"%s\", replyDomain=\"%s\", context=%p)\n",
 631           sdRef, flags, interfaceIndex, errorCode,
 632           serviceName, regtype, replyDomain, context);
 633
 634  /*
 635   * Only process "add" data...
 636   */
 637
 638   if (errorCode != kDNSServiceErr_NoError || !(flags & kDNSServiceFlagsAdd))
 639     return;
 640
 641  /*
 642   * Get the device...
 643   */
 644
 645   device = get_device((cups_array_t *)context, serviceName, regtype,
 646                       replyDomain);
 647
 648  /*
 649   * Hide locally-registered devices...
 650   */
 651
 652   fprintf(stderr, "DEBUG: Hiding local printer \"%s\"...\n",
 653           device->fullName);
 654   device->sent = 1;
 655 }
 656 #endif /* HAVE_DNSSD */
 657
 658
 659 #ifdef HAVE_AVAHI
 660 /*
 661  * 'browse_callback()' - Browse devices.
 662  */
 663
 664 static void
 665 browse_callback(
 666     AvahiServiceBrowser    *browser,    /* I - Browser */
 667     AvahiIfIndex           interface,   /* I - Interface index (unused) */
 668     AvahiProtocol          protocol,    /* I - Network protocol (unused) */
 669     AvahiBrowserEvent      event,       /* I - What happened */
 670     const char             *name,       /* I - Service name */
 671     const char             *type,       /* I - Registration type */
 672     const char             *domain,     /* I - Domain */
 673     AvahiLookupResultFlags flags,       /* I - Flags */
 674     void                   *context)    /* I - Devices array */
 675 {
 676   AvahiClient *client = avahi_service_browser_get_client(browser);
 677                                         /* Client information */
 678
 679
 680   (void)interface;
 681   (void)protocol;
 682   (void)context;
 683
 684   switch (event)
 685   {
 686     case AVAHI_BROWSER_FAILURE:
 687         fprintf(stderr, "DEBUG: browse_callback: %s\n",
 688                 avahi_strerror(avahi_client_errno(client)));
 689         avahi_simple_poll_quit(simple_poll);
 690         break;
 691
 692     case AVAHI_BROWSER_NEW:
 693        /*
 694         * This object is new on the network.
 695         */
 696
 697         if (flags & AVAHI_LOOKUP_RESULT_LOCAL)
 698         {
 699          /*
 700           * This comes from the local machine so ignore it.
 701           */
 702
 703           fprintf(stderr, "DEBUG: Ignoring local service %s.\n", name);
 704         }
 705         else
 706         {
 707          /*
 708           * Create a device entry for it if it doesn't yet exist.
 709           */
 710
 711           get_device((cups_array_t *)context, name, type, domain);
 712         }
 713         break;
 714
 715     case AVAHI_BROWSER_REMOVE:
 716     case AVAHI_BROWSER_CACHE_EXHAUSTED:
 717         break;
 718
 719     case AVAHI_BROWSER_ALL_FOR_NOW:
 720         browsers--;
 721         break;
 722   }
 723 }
 724
 725
 726 /*
 727  * 'client_callback()' - Avahi client callback function.
 728  */
 729
 730 static void
 731 client_callback(
 732     AvahiClient      *client,           /* I - Client information (unused) */
 733     AvahiClientState state,             /* I - Current state */
 734     void             *context)          /* I - User data (unused) */
 735 {
 736   (void)client;
 737   (void)context;
 738
 739  /*
 740   * If the connection drops, quit.
 741   */
 742
 743   if (state == AVAHI_CLIENT_FAILURE)
 744   {
 745     fputs("DEBUG: Avahi connection failed.\n", stderr);
 746     avahi_simple_poll_quit(simple_poll);
 747   }
 748 }
 749 #endif /* HAVE_AVAHI */
 750
 751
 752 /*
 753  * 'compare_devices()' - Compare two devices.
 754  */
 755
 756 static int                              /* O - Result of comparison */
 757 compare_devices(cups_device_t *a,       /* I - First device */
 758                 cups_device_t *b)       /* I - Second device */
 759 {
 760   return (strcmp(a->name, b->name));
 761 }
 762
 763
 764 /*
 765  * 'exec_backend()' - Execute the backend that corresponds to the
 766  *                    resolved service name.
 767  */
 768
 769 static void
 770 exec_backend(char **argv)               /* I - Command-line arguments */
 771 {
 772   const char    *resolved_uri,          /* Resolved device URI */
 773                 *cups_serverbin;        /* Location of programs */
 774   char          scheme[1024],           /* Scheme from URI */
 775                 *ptr,                   /* Pointer into scheme */
 776                 filename[1024];         /* Backend filename */
 777
 778
 779  /*
 780   * Resolve the device URI...
 781   */
 782
 783   job_canceled = -1;
 784
 785   while ((resolved_uri = cupsBackendDeviceURI(argv)) == NULL)
 786   {
 787     _cupsLangPrintFilter(stderr, "INFO", _("Unable to locate printer."));
 788     sleep(10);
 789
 790     if (getenv("CLASS") != NULL)
 791       exit(CUPS_BACKEND_FAILED);
 792   }
 793
 794  /*
 795   * Extract the scheme from the URI...
 796   */
 797
 798   strlcpy(scheme, resolved_uri, sizeof(scheme));
 799   if ((ptr = strchr(scheme, ':')) != NULL)
 800     *ptr = '\0';
 801
 802  /*
 803   * Get the filename of the backend...
 804   */
 805
 806   if ((cups_serverbin = getenv("CUPS_SERVERBIN")) == NULL)
 807     cups_serverbin = CUPS_SERVERBIN;
 808
 809   snprintf(filename, sizeof(filename), "%s/backend/%s", cups_serverbin, scheme);
 810
 811  /*
 812   * Overwrite the device URI and run the new backend...
 813   */
 814
 815   setenv("DEVICE_URI", resolved_uri, 1);
 816
 817   argv[0] = (char *)resolved_uri;
 818
 819   fprintf(stderr, "DEBUG: Executing backend \"%s\"...\n", filename);
 820
 821   execv(filename, argv);
 822
 823   fprintf(stderr, "ERROR: Unable to execute backend \"%s\": %s\n", filename,
 824           strerror(errno));
 825   exit(CUPS_BACKEND_STOP);
 826 }
 827
 828
 829 /*
 830  * 'device_type()' - Get DNS-SD type enumeration from string.
 831  */
 832
 833 static cups_devtype_t                   /* O - Device type */
 834 device_type(const char *regtype)        /* I - Service registration type */
 835 {
 836 #ifdef HAVE_AVAHI
 837   if (!strcmp(regtype, "_ipp._tcp"))
 838     return (CUPS_DEVICE_IPP);
 839   else if (!strcmp(regtype, "_ipps._tcp") ||
 840            !strcmp(regtype, "_ipp-tls._tcp"))
 841     return (CUPS_DEVICE_IPPS);
 842   else if (!strcmp(regtype, "_fax-ipp._tcp"))
 843     return (CUPS_DEVICE_FAX_IPP);
 844   else if (!strcmp(regtype, "_printer._tcp"))
 845     return (CUPS_DEVICE_PDL_DATASTREAM);
 846 #else
 847   if (!strcmp(regtype, "_ipp._tcp."))
 848     return (CUPS_DEVICE_IPP);
 849   else if (!strcmp(regtype, "_ipps._tcp.") ||
 850            !strcmp(regtype, "_ipp-tls._tcp."))
 851     return (CUPS_DEVICE_IPPS);
 852   else if (!strcmp(regtype, "_fax-ipp._tcp."))
 853     return (CUPS_DEVICE_FAX_IPP);
 854   else if (!strcmp(regtype, "_printer._tcp."))
 855     return (CUPS_DEVICE_PRINTER);
 856   else if (!strcmp(regtype, "_pdl-datastream._tcp."))
 857     return (CUPS_DEVICE_PDL_DATASTREAM);
 858 #endif /* HAVE_AVAHI */
 859
 860   return (CUPS_DEVICE_RIOUSBPRINT);
 861 }
 862
 863
 864 /*
 865  * 'get_device()' - Create or update a device.
 866  */
 867
 868 static cups_device_t *                  /* O - Device */
 869 get_device(cups_array_t *devices,       /* I - Device array */
 870            const char   *serviceName,   /* I - Name of service/device */
 871            const char   *regtype,       /* I - Type of service */
 872            const char   *replyDomain)   /* I - Service domain */
 873 {
 874   cups_device_t key,                    /* Search key */
 875                 *device;                /* Device */
 876   char          fullName[kDNSServiceMaxDomainName];
 877                                         /* Full name for query */
 878
 879
 880  /*
 881   * See if this is a new device...
 882   */
 883
 884   key.name = (char *)serviceName;
 885   key.type = device_type(regtype);
 886
 887   for (device = cupsArrayFind(devices, &key);
 888        device;
 889        device = cupsArrayNext(devices))
 890     if (_cups_strcasecmp(device->name, key.name))
 891       break;
 892     else if (device->type == key.type)
 893     {
 894       if (!_cups_strcasecmp(device->domain, "local.") &&
 895           _cups_strcasecmp(device->domain, replyDomain))
 896       {
 897        /*
 898         * Update the .local listing to use the "global" domain name instead.
 899         * The backend will try local lookups first, then the global domain name.
 900         */
 901
 902         free(device->domain);
 903         device->domain = strdup(replyDomain);
 904
 905 #ifdef HAVE_DNSSD
 906         DNSServiceConstructFullName(fullName, device->name, regtype,
 907                                     replyDomain);
 908 #else /* HAVE_AVAHI */
 909         avahi_service_name_join(fullName, kDNSServiceMaxDomainName,
 910                                 serviceName, regtype, replyDomain);
 911 #endif /* HAVE_DNSSD */
 912
 913         free(device->fullName);
 914         device->fullName = strdup(fullName);
 915       }
 916
 917       return (device);
 918     }
 919
 920  /*
 921   * Yes, add the device...
 922   */
 923
 924 #ifdef HAVE_DNSSD
 925   DNSServiceConstructFullName(fullName, serviceName, regtype, replyDomain);
 926 #else /* HAVE_AVAHI */
 927   avahi_service_name_join(fullName, kDNSServiceMaxDomainName,
 928                            serviceName, regtype, replyDomain);
 929 #endif /* HAVE_DNSSD */
 930
 931   device           = calloc(sizeof(cups_device_t), 1);
 932   device->name     = strdup(serviceName);
 933   device->domain   = strdup(replyDomain);
 934   device->type     = key.type;
 935   device->priority = 50;
 936
 937   cupsArrayAdd(devices, device);
 938
 939  /*
 940   * Set the "full name" of this service, which is used for queries...
 941   */
 942
 943 #ifdef HAVE_DNSSD
 944   DNSServiceConstructFullName(fullName, serviceName, regtype, replyDomain);
 945 #else /* HAVE_AVAHI */
 946   avahi_service_name_join(fullName, kDNSServiceMaxDomainName,
 947                            serviceName, regtype, replyDomain);
 948 #endif /* HAVE_DNSSD */
 949
 950   device->fullName = strdup(fullName);
 951
 952   return (device);
 953 }
 954
 955
 956 #ifdef HAVE_AVAHI
 957 /*
 958  * 'poll_callback()' - Wait for input on the specified file descriptors.
 959  *
 960  * Note: This function is needed because avahi_simple_poll_iterate is broken
 961  *       and always uses a timeout of 0 (!) milliseconds.
 962  *       (Avahi Ticket #364)
 963  */
 964
 965 static int                              /* O - Number of file descriptors matching */
 966 poll_callback(
 967     struct pollfd *pollfds,             /* I - File descriptors */
 968     unsigned int  num_pollfds,          /* I - Number of file descriptors */
 969     int           timeout,              /* I - Timeout in milliseconds (unused) */
 970     void          *context)             /* I - User data (unused) */
 971 {
 972   int   val;                            /* Return value */
 973
 974
 975   (void)timeout;
 976   (void)context;
 977
 978   val = poll(pollfds, num_pollfds, 500);
 979
 980   if (val < 0)
 981     fprintf(stderr, "DEBUG: poll_callback: %s\n", strerror(errno));
 982   else if (val > 0)
 983     got_data = 1;
 984
 985   return (val);
 986 }
 987 #endif /* HAVE_AVAHI */
 988
 989
 990 #if defined(HAVE_DNSSD) || defined(HAVE_AVAHI)
 991 #  ifdef HAVE_DNSSD
 992 /*
 993  * 'query_callback()' - Process query data.
 994  */
 995
 996 static void
 997 query_callback(
 998     DNSServiceRef       sdRef,          /* I - Service reference */
 999     DNSServiceFlags     flags,          /* I - Data flags */
1000     uint32_t            interfaceIndex, /* I - Interface */
1001     DNSServiceErrorType errorCode,      /* I - Error, if any */
1002     const char          *fullName,      /* I - Full service name */
1003     uint16_t            rrtype,         /* I - Record type */
1004     uint16_t            rrclass,        /* I - Record class */
1005     uint16_t            rdlen,          /* I - Length of record data */
1006     const void          *rdata,         /* I - Record data */
1007     uint32_t            ttl,            /* I - Time-to-live */
1008     void                *context)       /* I - Device */
1009 {
1010 #  else
1011 /*
1012  * 'query_callback()' - Process query data.
1013  */
1014
1015 static void
1016 query_callback(
1017     AvahiRecordBrowser     *browser,    /* I - Record browser */
1018     AvahiIfIndex           interfaceIndex,
1019                                         /* I - Interface index (unused) */
1020     AvahiProtocol          protocol,    /* I - Network protocol (unused) */
1021     AvahiBrowserEvent      event,       /* I - What happened? */
1022     const char             *fullName,   /* I - Service name */
1023     uint16_t               rrclass,     /* I - Record class */
1024     uint16_t               rrtype,      /* I - Record type */
1025     const void             *rdata,      /* I - TXT record */
1026     size_t                 rdlen,       /* I - Length of TXT record */
1027     AvahiLookupResultFlags flags,       /* I - Flags */
1028     void                   *context)    /* I - Device */
1029 {
1030   AvahiClient           *client = avahi_record_browser_get_client(browser);
1031                                         /* Client information */
1032 #  endif /* HAVE_DNSSD */
1033   char          *ptr;                   /* Pointer into string */
1034   cups_device_t *device = (cups_device_t *)context;
1035                                         /* Device */
1036   const uint8_t *data,                  /* Pointer into data */
1037                 *datanext,              /* Next key/value pair */
1038                 *dataend;               /* End of entire TXT record */
1039   uint8_t       datalen;                /* Length of current key/value pair */
1040   char          key[256],               /* Key string */
1041                 value[256],             /* Value string */
1042                 make_and_model[512],    /* Manufacturer and model */
1043                 model[256],             /* Model */
1044                 pdl[256],               /* PDL */
1045                 device_id[2048];        /* 1284 device ID */
1046
1047
1048 #  ifdef HAVE_DNSSD
1049   fprintf(stderr, "DEBUG2: query_callback(sdRef=%p, flags=%x, "
1050                   "interfaceIndex=%d, errorCode=%d, fullName=\"%s\", "
1051                   "rrtype=%u, rrclass=%u, rdlen=%u, rdata=%p, ttl=%u, "
1052                   "context=%p)\n",
1053           sdRef, flags, interfaceIndex, errorCode,
1054           fullName ? fullName : "(null)", rrtype, rrclass, rdlen, rdata, ttl,
1055           context);
1056
1057  /*
1058   * Only process "add" data...
1059   */
1060
1061   if (errorCode != kDNSServiceErr_NoError || !(flags & kDNSServiceFlagsAdd))
1062     return;
1063
1064 #  else
1065   fprintf(stderr, "DEBUG2: query_callback(browser=%p, interfaceIndex=%d, "
1066                   "protocol=%d, event=%d, fullName=\"%s\", rrclass=%u, "
1067                   "rrtype=%u, rdata=%p, rdlen=%u, flags=%x, context=%p)\n",
1068           browser, interfaceIndex, protocol, event,
1069           fullName ? fullName : "(null)", rrclass, rrtype, rdata,
1070           (unsigned)rdlen, flags, context);
1071
1072  /*
1073   * Only process "add" data...
1074   */
1075
1076   if (event != AVAHI_BROWSER_NEW)
1077   {
1078     if (event == AVAHI_BROWSER_FAILURE)
1079       fprintf(stderr, "ERROR: %s\n",
1080               avahi_strerror(avahi_client_errno(client)));
1081
1082     return;
1083   }
1084 #  endif /* HAVE_DNSSD */
1085
1086  /*
1087   * Pull out the priority and make and model from the TXT
1088   * record and save it...
1089   */
1090
1091   device_id[0]      = '\0';
1092   make_and_model[0] = '\0';
1093   pdl[0]            = '\0';
1094
1095   strlcpy(model, "Unknown", sizeof(model));
1096
1097   for (data = rdata, dataend = data + rdlen;
1098        data < dataend;
1099        data = datanext)
1100   {
1101    /*
1102     * Read a key/value pair starting with an 8-bit length.  Since the
1103     * length is 8 bits and the size of the key/value buffers is 256, we
1104     * don't need to check for overflow...
1105     */
1106
1107     datalen = *data++;
1108
1109     if (!datalen || (data + datalen) > dataend)
1110       break;
1111
1112     datanext = data + datalen;
1113
1114     for (ptr = key; data < datanext && *data != '='; data ++)
1115       *ptr++ = (char)*data;
1116     *ptr = '\0';
1117
1118     if (data < datanext && *data == '=')
1119     {
1120       data ++;
1121
1122       if (data < datanext)
1123         memcpy(value, data, (size_t)(datanext - data));
1124       value[datanext - data] = '\0';
1125
1126       fprintf(stderr, "DEBUG2: query_callback: \"%s=%s\".\n",
1127               key, value);
1128     }
1129     else
1130     {
1131       fprintf(stderr, "DEBUG2: query_callback: \"%s\" with no value.\n",
1132               key);
1133       continue;
1134     }
1135
1136     if (!_cups_strncasecmp(key, "usb_", 4))
1137     {
1138      /*
1139       * Add USB device ID information...
1140       */
1141
1142       ptr = device_id + strlen(device_id);
1143       snprintf(ptr, sizeof(device_id) - (size_t)(ptr - device_id), "%s:%s;", key + 4, value);
1144     }
1145
1146     if (!_cups_strcasecmp(key, "usb_MFG") || !_cups_strcasecmp(key, "usb_MANU") ||
1147         !_cups_strcasecmp(key, "usb_MANUFACTURER"))
1148       strlcpy(make_and_model, value, sizeof(make_and_model));
1149     else if (!_cups_strcasecmp(key, "usb_MDL") || !_cups_strcasecmp(key, "usb_MODEL"))
1150       strlcpy(model, value, sizeof(model));
1151     else if (!_cups_strcasecmp(key, "product") && !strstr(value, "Ghostscript"))
1152     {
1153       if (value[0] == '(')
1154       {
1155        /*
1156         * Strip parenthesis...
1157         */
1158
1159         if ((ptr = value + strlen(value) - 1) > value && *ptr == ')')
1160           *ptr = '\0';
1161
1162         strlcpy(model, value + 1, sizeof(model));
1163       }
1164       else
1165         strlcpy(model, value, sizeof(model));
1166     }
1167     else if (!_cups_strcasecmp(key, "ty"))
1168     {
1169       strlcpy(model, value, sizeof(model));
1170
1171       if ((ptr = strchr(model, ',')) != NULL)
1172         *ptr = '\0';
1173     }
1174     else if (!_cups_strcasecmp(key, "pdl"))
1175       strlcpy(pdl, value, sizeof(pdl));
1176     else if (!_cups_strcasecmp(key, "priority"))
1177       device->priority = atoi(value);
1178     else if ((device->type == CUPS_DEVICE_IPP ||
1179               device->type == CUPS_DEVICE_IPPS ||
1180               device->type == CUPS_DEVICE_PRINTER) &&
1181              !_cups_strcasecmp(key, "printer-type"))
1182     {
1183      /*
1184       * This is a CUPS printer!
1185       */
1186
1187       device->cups_shared = 1;
1188
1189       if (device->type == CUPS_DEVICE_PRINTER)
1190         device->sent = 1;
1191     }
1192     else if (!_cups_strcasecmp(key, "UUID"))
1193       device->uuid = strdup(value);
1194   }
1195
1196   if (device->device_id)
1197     free(device->device_id);
1198
1199   if (!device_id[0] && strcmp(model, "Unknown"))
1200   {
1201     if (make_and_model[0])
1202       snprintf(device_id, sizeof(device_id), "MFG:%s;MDL:%s;",
1203                make_and_model, model);
1204     else if (!_cups_strncasecmp(model, "designjet ", 10))
1205       snprintf(device_id, sizeof(device_id), "MFG:HP;MDL:%s", model + 10);
1206     else if (!_cups_strncasecmp(model, "stylus ", 7))
1207       snprintf(device_id, sizeof(device_id), "MFG:EPSON;MDL:%s", model + 7);
1208     else if ((ptr = strchr(model, ' ')) != NULL)
1209     {
1210      /*
1211       * Assume the first word is the make...
1212       */
1213
1214       memcpy(make_and_model, model, (size_t)(ptr - model));
1215       make_and_model[ptr - model] = '\0';
1216
1217       snprintf(device_id, sizeof(device_id), "MFG:%s;MDL:%s",
1218                make_and_model, ptr + 1);
1219     }
1220   }
1221
1222   if (device_id[0] &&
1223       !strstr(device_id, "CMD:") &&
1224       !strstr(device_id, "COMMAND SET:") &&
1225       (strstr(pdl, "application/pdf") ||
1226        strstr(pdl, "application/postscript") ||
1227        strstr(pdl, "application/vnd.hp-PCL") ||
1228        strstr(pdl, "image/")))
1229   {
1230     value[0] = '\0';
1231     if (strstr(pdl, "application/pdf"))
1232       strlcat(value, ",PDF", sizeof(value));
1233     if (strstr(pdl, "application/postscript"))
1234       strlcat(value, ",PS", sizeof(value));
1235     if (strstr(pdl, "application/vnd.hp-PCL"))
1236       strlcat(value, ",PCL", sizeof(value));
1237     for (ptr = strstr(pdl, "image/"); ptr; ptr = strstr(ptr, "image/"))
1238     {
1239       char *valptr = value + strlen(value);
1240                                         /* Pointer into value */
1241
1242       if (valptr < (value + sizeof(value) - 1))
1243         *valptr++ = ',';
1244
1245       ptr += 6;
1246       while (isalnum(*ptr & 255) || *ptr == '-' || *ptr == '.')
1247       {
1248         if (isalnum(*ptr & 255) && valptr < (value + sizeof(value) - 1))
1249           *valptr++ = (char)toupper(*ptr++ & 255);
1250         else
1251           break;
1252       }
1253
1254       *valptr = '\0';
1255     }
1256
1257     ptr = device_id + strlen(device_id);
1258     snprintf(ptr, sizeof(device_id) - (size_t)(ptr - device_id), "CMD:%s;", value + 1);
1259   }
1260
1261   if (device_id[0])
1262     device->device_id = strdup(device_id);
1263   else
1264     device->device_id = NULL;
1265
1266   if (device->make_and_model)
1267     free(device->make_and_model);
1268
1269   if (make_and_model[0])
1270   {
1271     strlcat(make_and_model, " ", sizeof(make_and_model));
1272     strlcat(make_and_model, model, sizeof(make_and_model));
1273
1274     device->make_and_model = strdup(make_and_model);
1275   }
1276   else
1277     device->make_and_model = strdup(model);
1278 }
1279 #endif /* HAVE_DNSSD || HAVE_AVAHI */
1280
1281
1282 /*
1283  * 'sigterm_handler()' - Handle termination signals.
1284  */
1285
1286 static void
1287 sigterm_handler(int sig)                /* I - Signal number (unused) */
1288 {
1289   (void)sig;
1290
1291   if (job_canceled)
1292     exit(CUPS_BACKEND_OK);
1293   else
1294     job_canceled = 1;
1295 }
1296
1297
1298 /*
1299  * 'unquote()' - Unquote a name string.
1300  */
1301
1302 static void
1303 unquote(char       *dst,                /* I - Destination buffer */
1304         const char *src,                /* I - Source string */
1305         size_t     dstsize)             /* I - Size of destination buffer */
1306 {
1307   char  *dstend = dst + dstsize - 1;    /* End of destination buffer */
1308
1309
1310   while (*src && dst < dstend)
1311   {
1312     if (*src == '\\')
1313     {
1314       src ++;
1315       if (isdigit(src[0] & 255) && isdigit(src[1] & 255) &&
1316           isdigit(src[2] & 255))
1317       {
1318         *dst++ = ((((src[0] - '0') * 10) + src[1] - '0') * 10) + src[2] - '0';
1319         src += 3;
1320       }
1321       else
1322         *dst++ = *src++;
1323     }
1324     else
1325       *dst++ = *src ++;
1326   }
1327
1328   *dst = '\0';
1329 }
1330
1331
1332 /*
1333  * End of "$Id: dnssd.c 12660 2015-05-22 19:09:57Z msweet $".
1334  */