Add a simple Bonjour/Avahi service registration class.

This should work out of the box on OS X but requires the Avahi Bonjour
compatability layer on *nix (libdns_sd).

Fairly straightforward service registration and removal that will be
used by a couple of upcoming features (and could easily be used as an
extra layer of 'advertising' by both mythfrontend and mythbackend).

mythtv/configure

@@ -138,6 +138,7 @@ Advanced options (experts only):
   --libxml2-path=HDRLOC    location of directory containing
                            'libxml/parser.h', not the
                            directory with parser.h [$libxml2_path_default]
+  --disable-libdns-sd      disable DNS Service Discovery (Bonjour/Zeroconf/Avahi)
 
   --with-bindings=LIST     install the bindings specified in the
                            comma-separated list
@@ -1354,6 +1355,7 @@ MYTHTV_CONFIG_LIST='
     asi
     joystick_menu
     libcec
+    libdns_sd
     libfftw3
     libmpeg2external
     libxml2
@@ -1998,6 +2000,7 @@ enable asi
 enable lamemp3
 enable libass
 enable libcec
+enable libdns_sd
 enable libxml2
 enable libudf
 enable lirc
@@ -4138,6 +4141,8 @@ int main(void) {
 EOF
 fi
 
+enabled libdns_sd && check_lib dns_sd.h DNSServiceRegister -ldns_sd || disable libdns_sd
+
 if enabled libxml2 ; then
    if pkg-config --exists libxml-2.0 ; then
         libxml2_path=`pkg-config --cflags-only-I libxml-2.0|sed -n "s/-I\([^ ]*\) *$/\1/p"`
@@ -4569,6 +4574,7 @@ echo "multi threaded libavcodec ${threads-no}"
 if enabled frontend; then
   echo "libxml2 support           ${libxml2-no} [$libxml2_path]"
 fi
+echo "libdns_sd (Bonjour)       ${libdns_sd-no}"
 echo "Frontend                  ${frontend-no}"
 echo "Backend                   ${backend-no}"
 echo "OpenGL ES 2.0             ${opengles-no}"
@@ -4879,6 +4885,10 @@ if enabled libxml2; then
   fi
 fi
 
+if enabled libdns_sd; then
+  append CONFIG_DEFINES "using_libdns_sd"
+fi
+
 if enabled libudf; then
   append CCONFIG "using_libudf"
 fi

mythtv/libs/libmythbase/bonjourregister.cpp

@@ -0,0 +1,102 @@
+#include <QSocketNotifier>
+#include <QtEndian>
+#include "mythlogging.h"
+#include "bonjourregister.h"
+
+#define LOC QString("Bonjour: ")
+
+BonjourRegister::BonjourRegister(QObject *parent)
+  : QObject(parent), m_dnssref(0), m_socket(NULL)
+{
+}
+
+BonjourRegister::~BonjourRegister()
+{
+    if (m_socket)
+        m_socket->setEnabled(false);
+
+    if (m_dnssref)
+    {
+        LOG(VB_GENERAL, LOG_INFO, LOC + "De-registering service.");
+        DNSServiceRefDeallocate(m_dnssref);
+    }
+    m_dnssref = 0;
+
+    m_socket->deleteLater();
+    m_socket = NULL;
+}
+
+bool BonjourRegister::Register(uint16_t port, const QByteArray &type,
+                              const QByteArray &name, const QByteArray &txt)
+{
+    if (m_dnssref)
+    {
+        LOG(VB_GENERAL, LOG_WARNING, LOC + "Service already registered.");
+        return true;
+    }
+
+    uint16_t qport = qToBigEndian(port);
+    DNSServiceErrorType res =
+        DNSServiceRegister(&m_dnssref, 0, 0, (const char*)name.data(),
+                           (const char*)type.data(),
+                           NULL, 0, qport, txt.size(), (void*)txt.data(),
+                           BonjourCallback, this);
+
+    if (kDNSServiceErr_NoError != res)
+    {
+        LOG(VB_GENERAL, LOG_ERR, LOC + QString("Error: %1").arg(res));
+    }
+    else
+    {
+        int fd = DNSServiceRefSockFD(m_dnssref);
+        if (fd != -1)
+        {
+            m_socket = new QSocketNotifier(fd, QSocketNotifier::Read, this);
+            m_socket->setEnabled(true);
+            connect(m_socket, SIGNAL(activated(int)),
+                    this, SLOT(socketReadyRead()));
+            return true;
+        }
+    }
+
+    LOG(VB_GENERAL, LOG_ERR, LOC + "Failed to register service.");
+    return false;
+}
+
+
+void BonjourRegister::socketReadyRead()
+{
+    DNSServiceErrorType res = DNSServiceProcessResult(m_dnssref);
+    if (kDNSServiceErr_NoError != res)
+        LOG(VB_GENERAL, LOG_ERR, LOC + QString("Read Error: %1").arg(res));
+}
+
+
+void BonjourRegister::BonjourCallback(DNSServiceRef ref, DNSServiceFlags flags,
+                                      DNSServiceErrorType errorcode,
+                                      const char *name, const char *type,
+                                      const char *domain, void *object)
+{
+    (void)ref;
+    (void)flags;
+
+    BonjourRegister *bonjour = static_cast<BonjourRegister *>(object);
+    if (kDNSServiceErr_NoError != errorcode)
+    {
+        LOG(VB_GENERAL, LOG_ERR, LOC + QString("Callback Error: %1")
+            .arg(errorcode));
+    }
+    else if (bonjour)
+    {
+        LOG(VB_GENERAL, LOG_INFO, LOC +
+            QString("Service registration complete: name '%1' type '%2' domain: '%3'")
+            .arg(QString::fromUtf8(name)).arg(QString::fromUtf8(type))
+            .arg(QString::fromUtf8(domain)));
+    }
+    else
+    {
+        LOG(VB_GENERAL, LOG_ERR, LOC +
+            QString("BonjourCallback for unknown object."));
+    }
+}
+

mythtv/libs/libmythbase/bonjourregister.h

@@ -0,0 +1,32 @@
+#ifndef BONJOURREGISTER_H
+#define BONJOURREGISTER_H
+
+#include <QObject>
+#include <dns_sd.h>
+#include "mythbaseexp.h"
+
+class QSocketNotifier;
+
+class MBASE_PUBLIC BonjourRegister : public QObject
+{
+    Q_OBJECT
+  public:
+    BonjourRegister(QObject *parent = 0);
+   ~BonjourRegister();
+
+    bool Register(uint16_t port, const QByteArray &type, const QByteArray &name,
+                  const QByteArray &txt);
+
+  private slots:
+    void socketReadyRead();
+
+  private:
+    static void DNSSD_API BonjourCallback(DNSServiceRef ref,
+                                          DNSServiceFlags flags,
+                                          DNSServiceErrorType errorcode,
+                                          const char *name, const char *type,
+                                          const char *domain, void *object);
+    DNSServiceRef    m_dnssref;
+    QSocketNotifier *m_socket;
+};
+#endif

mythtv/libs/libmythbase/libmythbase.pro

@@ -63,7 +63,7 @@ inc.files += mythcoreutil.h mythlocale.h mythdownloadmanager.h
 inc.files += mythtranslation.h iso639.h iso3166.h mythmedia.h util.h
 inc.files += mythcdrom.h autodeletedeque.h dbutil.h mythhttppool.h mythdeque.h
 inc.files += referencecounter.h mythcommandlineparser.h mthread.h mthreadpool.h
-inc.files += filesysteminfo.h hardwareprofile.h
+inc.files += filesysteminfo.h hardwareprofile.h bonjourregister.h
 
 # Allow both #include <blah.h> and #include <libmythbase/blah.h>
 inc2.path  = $${PREFIX}/include/mythtv/libmythbase
@@ -100,6 +100,13 @@ use_hidesyms {
     QMAKE_CXXFLAGS += -fvisibility=hidden
 }
 
+using_libdns_sd {
+    DEFINES += USING_LIBDNS_SD
+    HEADERS += bonjourregister.h
+    SOURCES += bonjourregister.cpp
+    LIBS += -ldns_sd
+}
+
 using_libudf {
     DEFINES += USING_LIBUDF
     LIBS += -ludf