cups/patches/cups-1.5.2-avahi-2-backend.patch

diff -up cups-1.5.2/backend/dnssd.c.avahi-2-backend cups-1.5.2/backend/dnssd.c
--- cups-1.5.2/backend/dnssd.c.avahi-2-backend	2012-02-06 11:09:08.318644741 +0100
+++ cups-1.5.2/backend/dnssd.c	2012-02-06 11:09:08.326644641 +0100
@@ -15,14 +15,21 @@
  *
  * Contents:
  *
+ *   next_txt_record()       - Get next TXT record from a cups_txt_records_t.
+ *   parse_txt_record_pair() - Read key/value pair in cups_txt_records_t.
  *   main()                  - Browse for printers.
  *   browse_callback()       - Browse devices.
  *   browse_local_callback() - Browse local devices.
  *   compare_devices()       - Compare two devices.
  *   exec_backend()          - Execute the backend that corresponds to the
  *                             resolved service name.
+ *   device_type()           - Get DNS-SD type enumeration from string.
  *   get_device()            - Create or update a device.
  *   query_callback()        - Process query data.
+ *   avahi_client_callback() - Avahi client callback function.
+ *   avahi_query_callback()  - Avahi query callback function.
+ *   avahi_browse_callback() - Avahi browse callback function.
+ *   find_device()           - Find a device from its name and domain.
  *   sigterm_handler()       - Handle termination signals...
  *   unquote()               - Unquote a name string.
  */
@@ -33,7 +40,18 @@
 
 #include "backend-private.h"
 #include <cups/array.h>
-#include <dns_sd.h>
+#ifdef HAVE_DNSSD
+#  include <dns_sd.h>
+#endif /* HAVE_DNSSD */
+#ifdef HAVE_AVAHI
+#  include <avahi-client/client.h>
+#  include <avahi-client/lookup.h>
+#  include <avahi-common/simple-watch.h>
+#  include <avahi-common/domain.h>
+#  include <avahi-common/error.h>
+#  include <avahi-common/malloc.h>
+#define kDNSServiceMaxDomainName AVAHI_DOMAIN_NAME_MAX
+#endif /* HAVE_AVAHI */
 
 
 /*
@@ -53,7 +71,12 @@ typedef enum
 
 typedef struct
 {
+#ifdef HAVE_DNSSD
   DNSServiceRef	ref;			/* Service reference for resolve */
+#endif /* HAVE_DNSSD */
+#ifdef HAVE_AVAHI
+  int		resolved;		/* Did we resolve the device? */
+#endif /* HAVE_AVAHI */
   char		*name,			/* Service name */
 		*domain,		/* Domain name */
 		*fullName,		/* Full name */
@@ -65,6 +88,20 @@ typedef struct
 		sent;			/* Did we list the device? */
 } cups_device_t;
 
+typedef struct
+{
+  char key[256];
+  char value[256];
+
+#ifdef HAVE_DNSSD
+  const uint8_t *data;
+  const uint8_t *datanext;
+  const uint8_t *dataend;
+#else /* HAVE_AVAHI */
+  AvahiStringList *txt;
+#endif /* HAVE_DNSSD */
+} cups_txt_records_t;
+
 
 /*
  * Local globals...
@@ -78,6 +115,7 @@ static int		job_canceled = 0;
  * Local functions...
  */
 
+#ifdef HAVE_DNSSD
 static void		browse_callback(DNSServiceRef sdRef,
 			                DNSServiceFlags flags,
 				        uint32_t interfaceIndex,
@@ -93,12 +131,6 @@ static void		browse_local_callback(DNSSe
 					      const char *regtype,
 					      const char *replyDomain,
 					      void *context);
-static int		compare_devices(cups_device_t *a, cups_device_t *b);
-static void		exec_backend(char **argv);
-static cups_device_t	*get_device(cups_array_t *devices,
-			            const char *serviceName,
-			            const char *regtype,
-				    const char *replyDomain);
 static void		query_callback(DNSServiceRef sdRef,
 			               DNSServiceFlags flags,
 				       uint32_t interfaceIndex,
@@ -107,9 +139,118 @@ static void		query_callback(DNSServiceRe
 				       uint16_t rrclass, uint16_t rdlen,
 				       const void *rdata, uint32_t ttl,
 				       void *context);
+#endif /* HAVE_DNSSD */
+#ifdef HAVE_AVAHI
+static void		avahi_client_callback (AvahiClient *client,
+					       AvahiClientState state,
+					       void *context);
+static void		avahi_browse_callback (AvahiServiceBrowser *browser,
+					       AvahiIfIndex interface,
+					       AvahiProtocol protocol,
+					       AvahiBrowserEvent event,
+					       const char *serviceName,
+					       const char *regtype,
+					       const char *replyDomain,
+					       AvahiLookupResultFlags flags,
+					       void *context);
+#endif /* HAVE_AVAHI */
+
+static cups_device_t *	find_device (cups_array_t *devices,
+				     cups_txt_records_t *txt,
+				     cups_device_t *dkey);
+static int		compare_devices(cups_device_t *a, cups_device_t *b);
+static void		exec_backend(char **argv);
+static cups_device_t	*get_device(cups_array_t *devices,
+			            const char *serviceName,
+			            const char *regtype,
+				    const char *replyDomain);
 static void		sigterm_handler(int sig);
 static void		unquote(char *dst, const char *src, size_t dstsize);
 
+#ifdef HAVE_AVAHI
+static AvahiSimplePoll *simple_poll = NULL;
+static int avahi_got_callback;
+#endif /* HAVE_AVAHI */
+
+
+/*
+ * 'next_txt_record()' - Get next TXT record from a cups_txt_records_t.
+ */
+
+static cups_txt_records_t *
+next_txt_record (cups_txt_records_t *txt)
+{
+#ifdef HAVE_DNSSD
+  txt->data = txt->datanext;
+#else /* HAVE_AVAHI */
+  txt->txt = avahi_string_list_get_next (txt->txt);
+  if (txt->txt == NULL)
+    return NULL;
+#endif /* HAVE_DNSSD */
+
+  return txt;
+}
+
+
+/*
+ * 'parse_txt_record_pair()' - Read key/value pair in cups_txt_records_t.
+ */
+
+static int
+parse_txt_record_pair (cups_txt_records_t *txt)
+{
+#ifdef HAVE_DNSSD
+  uint8_t	datalen;
+  uint8_t	*data = txt->data;
+  char		*ptr;
+
+ /*
+  * Read a key/value pair starting with an 8-bit length.  Since the
+  * length is 8 bits and the size of the key/value buffers is 256, we
+  * don't need to check for overflow...
+  */
+
+  datalen = *data++;
+  if (!datalen || (data + datalen) >= txt->dataend)
+    return NULL;
+  txt->datanext = data + datalen;
+
+  for (ptr = txt->key; data < txt->datanext && *data != '='; data ++)
+    *ptr++ = *data;
+  *ptr = '\0';
+
+  if (data < txt->datanext && *data == '=')
+  {
+    data++;
+
+    if (data < datanext)
+      memcpy (txt->value, data, txt->datanext - data);
+    value[txt->datanext - data] = '\0';
+  }
+  else
+    return 1;
+#else /* HAVE_AVAHI */
+  char *key, *value;
+  size_t len;
+  avahi_string_list_get_pair (txt->txt, &key, &value, &len);
+  if (len > sizeof (txt->value) - 1)
+    len = sizeof (txt->value) - 1;
+
+  memcpy (txt->value, value, len);
+  txt->value[len] = '\0';
+  len = strlen (key);
+  if (len > sizeof (txt->key) - 1)
+    len = sizeof (txt->key) - 1;
+
+  memcpy (txt->key, key, len);
+  txt->key[len] = '\0';
+  avahi_free (key);
+  avahi_free (value);
+#endif /* HAVE_AVAHI */
+
+  return 0;
+}
+
 
 /*
  * 'main()' - Browse for printers.
@@ -120,6 +261,13 @@ main(int  argc,				/* I - Number of comm
      char *argv[])			/* I - Command-line arguments */
 {
   const char	*name;			/* Backend name */
+  cups_array_t	*devices;		/* Device array */
+  cups_device_t	*device;		/* Current device */
+  char		uriName[1024];		/* Unquoted fullName for URI */
+#ifdef HAVE_DNSSD
+  int		fd;			/* Main file descriptor */
+  fd_set	input;			/* Input set for select() */
+  struct timeval timeout;		/* Timeout for select() */
   DNSServiceRef	main_ref,		/* Main service reference */
 		fax_ipp_ref,		/* IPP fax service reference */
 		ipp_ref,		/* IPP service reference */
@@ -133,12 +281,11 @@ main(int  argc,				/* I - Number of comm
 		pdl_datastream_ref,	/* AppSocket service reference */
 		printer_ref,		/* LPD service reference */
 		riousbprint_ref;	/* Remote IO service reference */
-  int		fd;			/* Main file descriptor */
-  fd_set	input;			/* Input set for select() */
-  struct timeval timeout;		/* Timeout for select() */
-  cups_array_t	*devices;		/* Device array */
-  cups_device_t	*device;		/* Current device */
-  char		uriName[1024];		/* Unquoted fullName for URI */
+#endif /* HAVE_DNSSD */
+#ifdef HAVE_AVAHI
+  AvahiClient	*client;
+  int		error;
+#endif /* HAVE_AVAHI */
 #if defined(HAVE_SIGACTION) && !defined(HAVE_SIGSET)
   struct sigaction action;		/* Actions for POSIX signals */
 #endif /* HAVE_SIGACTION && !HAVE_SIGSET */
@@ -198,6 +345,49 @@ main(int  argc,				/* I - Number of comm
   * Browse for different kinds of printers...
   */
 
+#ifdef HAVE_AVAHI
+  if ((simple_poll = avahi_simple_poll_new ()) == NULL)
+  {
+    perror ("ERROR: Unable to create avahi simple poll object");
+    return (1);
+  }
+
+  client = avahi_client_new (avahi_simple_poll_get (simple_poll),
+			     0, avahi_client_callback, NULL, &error);
+  if (!client)
+  {
+    perror ("DEBUG: Unable to create avahi client");
+    return (0);
+  }
+
+  avahi_service_browser_new (client, AVAHI_IF_UNSPEC,
+			     AVAHI_PROTO_UNSPEC,
+			     "_fax-ipp._tcp", NULL, 0,
+			     avahi_browse_callback, devices);
+  avahi_service_browser_new (client, AVAHI_IF_UNSPEC,
+			     AVAHI_PROTO_UNSPEC,
+			     "_ipp._tcp", NULL, 0,
+			     avahi_browse_callback, devices);
+  avahi_service_browser_new (client, AVAHI_IF_UNSPEC,
+			     AVAHI_PROTO_UNSPEC,
+			     "_ipp-tls._tcp", NULL, 0,
+			     avahi_browse_callback, devices);
+  avahi_service_browser_new (client, AVAHI_IF_UNSPEC,
+			     AVAHI_PROTO_UNSPEC,
+			     "_pdl-datastream._tcp",
+			     NULL, 0,
+			     avahi_browse_callback,
+			     devices);
+  avahi_service_browser_new (client, AVAHI_IF_UNSPEC,
+			     AVAHI_PROTO_UNSPEC,
+			     "_printer._tcp", NULL, 0,
+			     avahi_browse_callback, devices);
+  avahi_service_browser_new (client, AVAHI_IF_UNSPEC,
+			     AVAHI_PROTO_UNSPEC,
+			     "_riousbprint._tcp", NULL, 0,
+			     avahi_browse_callback, devices);
+#endif /* HAVE_AVAHI */
+#ifdef HAVE_DNSSD
   if (DNSServiceCreateConnection(&main_ref) != kDNSServiceErr_NoError)
   {
     perror("ERROR: Unable to create service connection");
@@ -258,6 +448,7 @@ main(int  argc,				/* I - Number of comm
   riousbprint_ref = main_ref;
   DNSServiceBrowse(&riousbprint_ref, kDNSServiceFlagsShareConnection, 0,
                    "_riousbprint._tcp", NULL, browse_callback, devices);
+#endif /* HAVE_DNSSD */
 
  /*
   * Loop until we are killed...
@@ -265,6 +456,9 @@ main(int  argc,				/* I - Number of comm
 
   while (!job_canceled)
   {
+    int announce = 0;
+
+#ifdef HAVE_DNSSD
     FD_ZERO(&input);
     FD_SET(fd, &input);
 
@@ -284,11 +478,35 @@ main(int  argc,				/* I - Number of comm
     }
     else
     {
+      announce = 1;
+    }
+#else /* HAVE_AVAHI */
+    int r;
+    avahi_got_callback = 0;
+    r = avahi_simple_poll_iterate (simple_poll, 1);
+    if (r != 0 && r != EINTR)
+    {
+     /*
+      * We've been told to exit the loop.  Perhaps the connection to
+      * avahi failed.
+      */
+
+      break;
+    }
+
+    if (avahi_got_callback)
+      announce = 1;
+#endif /* HAVE_DNSSD */
+
+    if (announce)
+    {
      /*
       * Announce any devices we've found...
       */
 
+#ifdef HAVE_DNSSD
       DNSServiceErrorType status;	/* DNS query status */
+#endif /* HAVE_DNSSD */
       cups_device_t *best;		/* Best matching device */
       char	device_uri[1024];	/* Device URI */
       int	count;			/* Number of queries */
@@ -302,6 +520,7 @@ main(int  argc,				/* I - Number of comm
         if (device->sent)
 	  sent ++;
 
+#ifdef HAVE_DNSSD
         if (device->ref)
 	  count ++;
 
@@ -333,14 +552,23 @@ main(int  argc,				/* I - Number of comm
 	      count ++;
           }
 	}
-	else if (!device->sent)
+	else
+#endif /* HAVE_DNSSD */
+#ifdef HAVE_AVAHI
+	if (!device->resolved)
+	  continue;
+        else
+#endif /* HAVE_AVAHI */
+	if (!device->sent)
 	{
+#ifdef HAVE_DNSSD
 	 /*
 	  * Got the TXT records, now report the device...
 	  */
 
 	  DNSServiceRefDeallocate(device->ref);
 	  device->ref = 0;
+#endif /* HAVE_DNSSD */
 
           if (!best)
 	    best = device;
@@ -401,6 +629,7 @@ main(int  argc,				/* I - Number of comm
 }
 
 
+#ifdef HAVE_DNSSD
 /*
  * 'browse_callback()' - Browse devices.
  */
@@ -489,6 +718,7 @@ browse_local_callback(
 	  device->fullName);
   device->sent = 1;
 }
+#endif /* HAVE_DNSSD */
 
 
 /*
@@ -569,6 +799,41 @@ exec_backend(char **argv)		/* I - Comman
 
 
 /*
+ * 'device_type()' - Get DNS-SD type enumeration from string.
+ */
+
+static int
+device_type (const char *regtype)
+{
+#ifdef HAVE_AVAHI
+  if (!strcmp(regtype, "_ipp._tcp"))
+    return (CUPS_DEVICE_IPP);
+  else if (!strcmp(regtype, "_ipps._tcp") ||
+	   !strcmp(regtype, "_ipp-tls._tcp"))
+    return (CUPS_DEVICE_IPPS);
+  else if (!strcmp(regtype, "_fax-ipp._tcp"))
+    return (CUPS_DEVICE_FAX_IPP);
+  else if (!strcmp(regtype, "_printer._tcp"))
+    return (CUPS_DEVICE_PDL_DATASTREAM);
+#else
+  if (!strcmp(regtype, "_ipp._tcp."))
+    return (CUPS_DEVICE_IPP);
+  else if (!strcmp(regtype, "_ipps._tcp.") ||
+	   !strcmp(regtype, "_ipp-tls._tcp."))
+    return (CUPS_DEVICE_IPPS);
+  else if (!strcmp(regtype, "_fax-ipp._tcp."))
+    return (CUPS_DEVICE_FAX_IPP);
+  else if (!strcmp(regtype, "_printer._tcp."))
+    return (CUPS_DEVICE_PRINTER);
+  else if (!strcmp(regtype, "_pdl-datastream._tcp."))
+    return (CUPS_DEVICE_PDL_DATASTREAM);
+#endif /* HAVE_AVAHI */
+
+  return (CUPS_DEVICE_RIOUSBPRINT);
+}
+
+
+/*
  * 'get_device()' - Create or update a device.
  */
 
@@ -589,20 +854,7 @@ get_device(cups_array_t *devices,	/* I -
   */
 
   key.name = (char *)serviceName;
-
-  if (!strcmp(regtype, "_ipp._tcp."))
-    key.type = CUPS_DEVICE_IPP;
-  else if (!strcmp(regtype, "_ipps._tcp.") ||
-	   !strcmp(regtype, "_ipp-tls._tcp."))
-    key.type = CUPS_DEVICE_IPPS;
-  else if (!strcmp(regtype, "_fax-ipp._tcp."))
-    key.type = CUPS_DEVICE_FAX_IPP;
-  else if (!strcmp(regtype, "_printer._tcp."))
-    key.type = CUPS_DEVICE_PRINTER;
-  else if (!strcmp(regtype, "_pdl-datastream._tcp."))
-    key.type = CUPS_DEVICE_PDL_DATASTREAM;
-  else
-    key.type = CUPS_DEVICE_RIOUSBPRINT;
+  key.type = device_type (regtype);
 
   for (device = cupsArrayFind(devices, &key);
        device;
@@ -622,8 +874,14 @@ get_device(cups_array_t *devices,	/* I -
         free(device->domain);
 	device->domain = strdup(replyDomain);
 
+#ifdef HAVE_DNSSD
 	DNSServiceConstructFullName(fullName, device->name, regtype,
 	                            replyDomain);
+#else /* HAVE_AVAHI */
+	avahi_service_name_join (fullName, kDNSServiceMaxDomainName,
+				 serviceName, regtype, replyDomain);
+#endif /* HAVE_DNSSD */
+
 	free(device->fullName);
 	device->fullName = strdup(fullName);
       }
@@ -643,6 +901,9 @@ get_device(cups_array_t *devices,	/* I -
   device->domain   = strdup(replyDomain);
   device->type     = key.type;
   device->priority = 50;
+#ifdef HAVE_AVAHI
+  device->resolved = 0;
+#endif /* HAVE_AVAHI */
 
   cupsArrayAdd(devices, device);
 
@@ -650,13 +911,20 @@ get_device(cups_array_t *devices,	/* I -
   * Set the "full name" of this service, which is used for queries...
   */
 
+#ifdef HAVE_DNSSD
   DNSServiceConstructFullName(fullName, serviceName, regtype, replyDomain);
+#else /* HAVE_AVAHI */
+  avahi_service_name_join (fullName, kDNSServiceMaxDomainName,
+			   serviceName, regtype, replyDomain);
+#endif /* HAVE_DNSSD */
+
   device->fullName = strdup(fullName);
 
   return (device);
 }
 
 
+#ifdef HAVE_DNSSD
 /*
  * 'query_callback()' - Process query data.
  */
@@ -680,7 +948,7 @@ query_callback(
 		*ptr;			/* Pointer into string */
   cups_device_t	dkey,			/* Search key */
 		*device;		/* Device */
-
+  cups_txt_records_t txt;
 
   fprintf(stderr, "DEBUG2: query_callback(sdRef=%p, flags=%x, "
                   "interfaceIndex=%d, errorCode=%d, fullName=\"%s\", "
@@ -714,94 +982,233 @@ query_callback(
   if ((ptr = strstr(name, "._")) != NULL)
     *ptr = '\0';
 
-  if (strstr(fullName, "_ipp._tcp."))
-    dkey.type = CUPS_DEVICE_IPP;
-  else if (strstr(fullName, "_ipps._tcp.") ||
-           strstr(fullName, "_ipp-tls._tcp."))
-    dkey.type = CUPS_DEVICE_IPPS;
-  else if (strstr(fullName, "_fax-ipp._tcp."))
-    dkey.type = CUPS_DEVICE_FAX_IPP;
-  else if (strstr(fullName, "_printer._tcp."))
-    dkey.type = CUPS_DEVICE_PRINTER;
-  else if (strstr(fullName, "_pdl-datastream._tcp."))
-    dkey.type = CUPS_DEVICE_PDL_DATASTREAM;
+  dkey.type = device_type (fullName);
+
+  txt.data = rdata;
+  txt.dataend = rdata + rdlen;
+  device = find_device ((cups_array_t *) context, &txt, &dkey);
+  if (!device)
+    fprintf(stderr, "DEBUG: Ignoring TXT record for \"%s\"...\n", fullName);
+}
+#endif /* HAVE_DNSSD */
+
+
+#ifdef HAVE_AVAHI
+/*
+ * 'avahi_client_callback()' - Avahi client callback function.
+ */
+
+static void
+avahi_client_callback(AvahiClient *client,
+		      AvahiClientState state,
+		      void *context)
+{
+ /*
+  * If the connection drops, quit.
+  */
+
+  if (state == AVAHI_CLIENT_FAILURE)
+  {
+    fprintf (stderr, "ERROR: Avahi connection failed\n");
+    avahi_simple_poll_quit (simple_poll);
+  }
+}
+
+
+/*
+ * 'avahi_query_callback()' - Avahi query callback function.
+ */
+
+static void
+avahi_query_callback(AvahiServiceResolver *resolver,
+		     AvahiIfIndex interface,
+		     AvahiProtocol protocol,
+		     AvahiResolverEvent event,
+		     const char *name,
+		     const char *type,
+		     const char *domain,
+		     const char *host_name,
+		     const AvahiAddress *address,
+		     uint16_t port,
+		     AvahiStringList *txt,
+		     AvahiLookupResultFlags flags,
+		     void *context)
+{
+  AvahiClient		*client;
+  cups_device_t		key,
+			*device;
+  char			uqname[1024],
+			*ptr;
+  cups_txt_records_t	txtr;
+
+  client = avahi_service_resolver_get_client (resolver);
+  if (event != AVAHI_RESOLVER_FOUND)
+  {
+    if (event == AVAHI_RESOLVER_FAILURE)
+    {
+      fprintf (stderr, "ERROR: %s\n",
+	       avahi_strerror (avahi_client_errno (client)));
+    }
+
+    avahi_service_resolver_free (resolver);
+    return;
+  }
+
+ /*
+  * Set search key for device.
+  */
+
+  key.name = uqname;
+  unquote (uqname, name, sizeof (uqname));
+  if ((ptr = strstr(name, "._")) != NULL)
+    *ptr = '\0';
+
+  key.domain = (char *) domain;
+  key.type = device_type (type);
+
+ /*
+  * Find the device and the the TXT information.
+  */
+
+  txtr.txt = txt;
+  device = find_device ((cups_array_t *) context, &txtr, &key);
+  if (device)
+  {
+   /*
+    * Let the main loop know to announce the device.
+    */
+
+    device->resolved = 1;
+    avahi_got_callback = 1;
+  }
   else
-    dkey.type = CUPS_DEVICE_RIOUSBPRINT;
+    fprintf (stderr, "DEBUG: Ignoring TXT record for \"%s\"...\n", name);
+
+  avahi_service_resolver_free (resolver);
+}
+
+
+/*
+ * 'avahi_browse_callback()' - Avahi browse callback function.
+ */
+
+static void
+avahi_browse_callback(AvahiServiceBrowser *browser,
+		      AvahiIfIndex interface,
+		      AvahiProtocol protocol,
+		      AvahiBrowserEvent event,
+		      const char *name,
+		      const char *type,
+		      const char *domain,
+		      AvahiLookupResultFlags flags,
+		      void *context)
+{
+  AvahiClient *client = avahi_service_browser_get_client (browser);
+
+  switch (event)
+  {
+  case AVAHI_BROWSER_FAILURE:
+    fprintf (stderr, "ERROR: %s\n",
+	     avahi_strerror (avahi_client_errno (client)));
+    avahi_simple_poll_quit (simple_poll);
+    return;
+
+  case AVAHI_BROWSER_NEW:
+   /*
+    * This object is new on the network.
+    */
+
+    if (flags & AVAHI_LOOKUP_RESULT_LOCAL)
+    {
+     /*
+      * This comes from the local machine so ignore it.
+      */
+
+      fprintf (stderr, "DEBUG: ignoring local service %s\n", name);
+    }
+    else
+    {
+     /*
+      * Create a device entry for it if it doesn't yet exist.
+      */
+
+      get_device ((cups_array_t *)context, name, type, domain);
+
+     /*
+      * Now look for a TXT entry.
+      */
+
+      if (avahi_service_resolver_new (client, interface, protocol,
+				      name, type, domain,
+				      AVAHI_PROTO_UNSPEC, 0,
+				      avahi_query_callback, context) == NULL)
+      {
+	fprintf (stderr, "ERROR: failed to resolve service %s: %s\n",
+		 name, avahi_strerror (avahi_client_errno (client)));
+      }
+    }
+
+    break;
+
+  case AVAHI_BROWSER_REMOVE:
+  case AVAHI_BROWSER_ALL_FOR_NOW:
+  case AVAHI_BROWSER_CACHE_EXHAUSTED:
+    break;
+  }
+}
+#endif /* HAVE_AVAHI */
+
 
-  for (device = cupsArrayFind(devices, &dkey);
+/*
+ * 'find_device()' - Find a device from its name and domain.
+ */
+
+static cups_device_t *
+find_device (cups_array_t *devices,
+	     cups_txt_records_t *txt,
+	     cups_device_t *dkey)
+{
+  cups_device_t	*device;
+  char		*ptr;
+
+  for (device = cupsArrayFind(devices, dkey);
        device;
        device = cupsArrayNext(devices))
   {
-    if (_cups_strcasecmp(device->name, dkey.name) ||
-        _cups_strcasecmp(device->domain, dkey.domain))
+    if (_cups_strcasecmp(device->name, dkey->name) ||
+        _cups_strcasecmp(device->domain, dkey->domain))
     {
       device = NULL;
       break;
     }
-    else if (device->type == dkey.type)
+    else if (device->type == dkey->type)
     {
      /*
       * Found it, pull out the priority and make and model from the TXT
       * record and save it...
       */
 
-      const uint8_t	*data,		/* Pointer into data */
-			*datanext,	/* Next key/value pair */
-			*dataend;	/* End of entire TXT record */
-      uint8_t		datalen;	/* Length of current key/value pair */
-      char		key[256],	/* Key string */
-			value[256],	/* Value string */
-			make_and_model[512],
+      char		make_and_model[512],
 				      	/* Manufacturer and model */
 			model[256],	/* Model */
-			device_id[2048];/* 1284 device ID */
-
+			device_id[2048]; /* 1284 device ID */
 
       device_id[0]      = '\0';
       make_and_model[0] = '\0';
 
       strcpy(model, "Unknown");
 
-      for (data = rdata, dataend = data + rdlen;
-           data < dataend;
-           data = datanext)
+      for (;;)
       {
-       /*
-        * Read a key/value pair starting with an 8-bit length.  Since the
-	* length is 8 bits and the size of the key/value buffers is 256, we
-	* don't need to check for overflow...
-	*/
-
-        datalen = *data++;
-
-        if (!datalen || (data + datalen) > dataend)
-	  break;
-
-        datanext = data + datalen;
-
-        for (ptr = key; data < datanext && *data != '='; data ++)
-	  *ptr++ = *data;
-	*ptr = '\0';
+	char *key;
+	char *value;
 
-	if (data < datanext && *data == '=')
-	{
-	  data ++;
-
-	  if (data < datanext)
-	    memcpy(value, data, datanext - data);
-	  value[datanext - data] = '\0';
+	if (parse_txt_record_pair (txt))
+	  goto next;
 
-	  fprintf(stderr, "DEBUG2: query_callback: \"%s=%s\".\n",
-	          key, value);
-	}
-	else
-	{
-	  fprintf(stderr, "DEBUG2: query_callback: \"%s\" with no value.\n",
-	          key);
-	  continue;
-	}
-
-        if (!_cups_strncasecmp(key, "usb_", 4))
+	key = txt->key;
+	value = txt->value;
+        if (!strncasecmp(key, "usb_", 4))
 	{
 	 /*
 	  * Add USB device ID information...
@@ -856,6 +1263,10 @@ query_callback(
 	  if (device->type == CUPS_DEVICE_PRINTER)
 	    device->sent = 1;
 	}
+
+      next:
+	if (next_txt_record (txt) == NULL)
+	  break;
       }
 
       if (device->device_id)
@@ -912,11 +1323,9 @@ query_callback(
     }
   }
 
-  if (!device)
-    fprintf(stderr, "DEBUG: Ignoring TXT record for \"%s\"...\n", fullName);
+  return device;
 }
 
-
 /*
  * 'sigterm_handler()' - Handle termination signals...
  */
diff -up cups-1.5.2/cups/http-support.c.avahi-2-backend cups-1.5.2/cups/http-support.c
--- cups-1.5.2/cups/http-support.c.avahi-2-backend	2011-09-26 20:46:46.000000000 +0200
+++ cups-1.5.2/cups/http-support.c	2012-02-06 11:09:08.327644629 +0100
@@ -43,6 +43,10 @@
  *   http_copy_decode()   - Copy and decode a URI.
  *   http_copy_encode()   - Copy and encode a URI.
  *   http_resolve_cb()    - Build a device URI for the given service name.
+ *   avahi_resolve_uri_client_cb()
+ *                        - Avahi client callback for resolving URI.
+ *   avahi_resolve_uri_resolver_cb()
+ *                        - Avahi resolver callback for resolving URI.
  */
 
 /*
@@ -60,6 +64,11 @@
 #    include <sys/select.h>
 #  endif /* WIN32 */
 #endif /* HAVE_DNSSD */
+#ifdef HAVE_AVAHI
+#  include <avahi-client/client.h>
+#  include <avahi-client/lookup.h>
+#  include <avahi-common/simple-watch.h>
+#endif /* HAVE_AVAHI */
 
 
 /*
@@ -127,6 +136,24 @@ static void DNSSD_API	http_resolve_cb(DN
 					void *context);
 #endif /* HAVE_DNSSD */
 
+#ifdef HAVE_AVAHI
+static void	avahi_resolve_uri_client_cb(AvahiClient *client,
+					    AvahiClientState state,
+					    void *simple_poll);
+static void	avahi_resolve_uri_resolver_cb(AvahiServiceResolver *resolver,
+					      AvahiIfIndex interface,
+					      AvahiProtocol protocol,
+					      AvahiResolverEvent event,
+					      const char *name,
+					      const char *type,
+					      const char *domain,
+					      const char *host_name,
+					      const AvahiAddress *address,
+					      uint16_t port,
+					      AvahiStringList *txt,
+					      AvahiLookupResultFlags flags,
+					      void *context);
+#endif /* HAVE_AVAHI */
 
 /*
  * 'httpAssembleURI()' - Assemble a uniform resource identifier from its
@@ -1431,6 +1458,9 @@ _httpResolveURI(
 
   if (strstr(hostname, "._tcp"))
   {
+#if defined(HAVE_DNSSD) || defined(HAVE_AVAHI)
+    char		*regtype,	/* Pointer to type in hostname */
+			*domain;	/* Pointer to domain in hostname */
 #ifdef HAVE_DNSSD
 #  ifdef WIN32
 #    pragma comment(lib, "dnssd.lib")
@@ -1449,6 +1479,17 @@ _httpResolveURI(
     fd_set		input_set;	/* Input set for select() */
     struct timeval	stimeout;	/* Timeout value for select() */
 #endif /* HAVE_POLL */
+#else /* HAVE_AVAHI */
+    AvahiSimplePoll	*simple_poll;
+    AvahiClient		*client;
+    int			error;
+    struct
+    {
+      AvahiSimplePoll	*poll;
+      _http_uribuf_t	uribuf;
+    } user_data;
+#endif /* HAVE_DNSSD */
+
 
     if (options & _HTTP_RESOLVE_STDERR)
       fprintf(stderr, "DEBUG: Resolving \"%s\"...\n", hostname);
@@ -1485,9 +1526,16 @@ _httpResolveURI(
     if (domain)
       *domain++ = '\0';
 
+#ifdef HAVE_DNSSD
     uribuf.buffer   = resolved_uri;
     uribuf.bufsize  = resolved_size;
     uribuf.options  = options;
+#else
+    user_data.uribuf.buffer = resolved_uri;
+    user_data.uribuf.bufsize = resolved_size;
+    user_data.uribuf.options = options;
+#endif
+
     resolved_uri[0] = '\0';
 
     DEBUG_printf(("6_httpResolveURI: Resolving hostname=\"%s\", regtype=\"%s\", "
@@ -1501,6 +1549,7 @@ _httpResolveURI(
 
     uri = NULL;
 
+#ifdef HAVE_DNSSD
     if (DNSServiceCreateConnection(&ref) == kDNSServiceErr_NoError)
     {
       localref = ref;
@@ -1608,6 +1657,36 @@ _httpResolveURI(
 
       DNSServiceRefDeallocate(ref);
     }
+#else /* HAVE_AVAHI */
+    if ((simple_poll = avahi_simple_poll_new ()) != NULL)
+    {
+      if ((client = avahi_client_new (avahi_simple_poll_get (simple_poll),
+				      0, avahi_resolve_uri_client_cb,
+				      &simple_poll, &error)) != NULL)
+      {
+	user_data.poll = simple_poll;
+	if (avahi_service_resolver_new (client, AVAHI_IF_UNSPEC,
+					AVAHI_PROTO_UNSPEC, hostname,
+					regtype, domain, AVAHI_PROTO_UNSPEC, 0,
+					avahi_resolve_uri_resolver_cb,
+					&user_data) != NULL)
+	{
+	  avahi_simple_poll_loop (simple_poll);
+
+	 /*
+	  * Collect the result.
+	  */
+
+	  if (resolved_uri[0])
+	    uri = resolved_uri;
+	}
+
+	avahi_client_free (client);
+      }
+
+      avahi_simple_poll_free (simple_poll);
+    }
+#endif /* HAVE_DNSSD */
 
     if (options & _HTTP_RESOLVE_STDERR)
     {
@@ -1619,13 +1698,13 @@ _httpResolveURI(
       fputs("STATE: -connecting-to-device,offline-report\n", stderr);
     }
 
-#else
+#else /* HAVE_DNSSD || HAVE_AVAHI */
    /*
     * No DNS-SD support...
     */
 
     uri = NULL;
-#endif /* HAVE_DNSSD */
+#endif /* HAVE_DNSSD || HAVE_AVAHI */
 
     if ((options & _HTTP_RESOLVE_STDERR) && !uri)
       _cupsLangPrintFilter(stderr, "ERROR", _("Unable to find printer."));
@@ -1914,6 +1993,116 @@ http_resolve_cb(
 #endif /* HAVE_DNSSD */
 
 
+#ifdef HAVE_AVAHI
+/*
+ * 'avahi_resolve_uri_client_cb()' - Avahi client callback for resolving URI.
+ */
+
+static void
+avahi_resolve_uri_client_cb (AvahiClient *client,
+			     AvahiClientState state,
+			     void *simple_poll)
+{
+  DEBUG_printf(("avahi_resolve_uri_client_callback(client=%p, state=%d, "
+		"simple_poll=%p)\n", client, state, simple_poll));
+
+  /*
+   * If the connection drops, quit.
+   */
+
+  if (state == AVAHI_CLIENT_FAILURE)
+    avahi_simple_poll_quit (simple_poll);
+}
+
+
+/*
+ * 'avahi_resolve_uri_resolver_cb()' - Avahi resolver callback for resolving
+ *                                     URI.
+ */
+
+static void
+avahi_resolve_uri_resolver_cb (AvahiServiceResolver *resolver,
+			       AvahiIfIndex interface,
+			       AvahiProtocol protocol,
+			       AvahiResolverEvent event,
+			       const char *name,
+			       const char *type,
+			       const char *domain,
+			       const char *host_name,
+			       const AvahiAddress *address,
+			       uint16_t port,
+			       AvahiStringList *txt,
+			       AvahiLookupResultFlags flags,
+			       void *context)
+{
+  const char		*scheme;	/* URI scheme */
+  char			rp[256];	/* Remote printer */
+  AvahiStringList	*pair;
+  char			*value;
+  size_t		valueLen = 0;
+  char			addr[AVAHI_ADDRESS_STR_MAX];
+  struct
+  {
+    AvahiSimplePoll	*poll;
+    _http_uribuf_t	uribuf;
+  }		*poll_uribuf = context;
+
+  DEBUG_printf(("avahi_resolve_uri_resolver_callback(resolver=%p, "
+		"interface=%d, protocol=%d, event=%d, name=\"%s\", "
+		"type=\"%s\", domain=\"%s\", host_name=\"%s\", address=%p, "
+		"port=%d, txt=%p, flags=%d, context=%p)\n",
+		resolver, interface, protocol, event, name, type, domain,
+		host_name, address, port, txt, flags, context));
+
+  if (event != AVAHI_RESOLVER_FOUND)
+  {
+    avahi_service_resolver_free (resolver);
+    avahi_simple_poll_quit (poll_uribuf->poll);
+    return;
+  }
+
+ /*
+  * Figure out the scheme from the full name...
+  */
+
+  if (strstr(type, "_ipp."))
+    scheme = "ipp";
+  else if (strstr(type, "_printer."))
+    scheme = "lpd";
+  else if (strstr(type, "_pdl-datastream."))
+    scheme = "socket";
+  else
+    scheme = "riousbprint";
+
+ /*
+  * Extract the "remote printer key from the TXT record...
+  */
+
+  if ((pair = avahi_string_list_find (txt, "rp")) != NULL)
+  {
+    avahi_string_list_get_pair (pair, NULL, &value, &valueLen);
+    rp[0] = '/';
+    memcpy (rp + 1, value, valueLen);
+    rp[valueLen + 1] = '\0';
+  }
+  else
+    rp[0] = '\0';
+
+ /*
+  * Assemble the final device URI...
+  */
+
+  avahi_address_snprint (addr, AVAHI_ADDRESS_STR_MAX, address);
+  httpAssembleURI(HTTP_URI_CODING_ALL, poll_uribuf->uribuf.buffer,
+		  poll_uribuf->uribuf.bufsize, scheme, NULL,
+		  addr, port, rp);
+  DEBUG_printf(("avahi_resolve_uri_resolver_callback: Resolved URI is \"%s\"\n",
+		poll_uribuf->uribuf.buffer));
+  avahi_simple_poll_quit (poll_uribuf->poll);
+}
+#endif /* HAVE_AVAHI */
+
+
 /*
  * End of "$Id: http-support.c 10017 2011-09-26 18:46:46Z mike $".
  */