Revert "remove macOS support"

This reverts commit 518ce0187a.

src/zeroconf/Bonjour.cxx

@@ -0,0 +1,76 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+// Copyright The Music Player Daemon Project
+
+#include "Bonjour.hxx"
+#include "util/Domain.hxx"
+#include "Log.hxx"
+
+#include <dns_sd.h>
+
+#include <stdexcept>
+
+#include <arpa/inet.h>
+
+static constexpr Domain bonjour_domain("bonjour");
+
+/**
+ * A wrapper for DNSServiceRegister() which returns the DNSServiceRef
+ * and throws on error.
+ */
+static DNSServiceRef
+RegisterBonjour(const char *name, const char *type, unsigned port,
+		DNSServiceRegisterReply callback, void *ctx)
+{
+	DNSServiceRef ref;
+	DNSServiceErrorType error = DNSServiceRegister(&ref,
+						       0, 0, name, type,
+						       nullptr, nullptr,
+						       htons(port), 0,
+						       nullptr,
+						       callback, ctx);
+
+	if (error != kDNSServiceErr_NoError)
+		throw std::runtime_error("DNSServiceRegister() failed");
+
+	return ref;
+}
+
+BonjourHelper::BonjourHelper(EventLoop &_loop, const char *name,
+			     const char *service_type, unsigned port)
+	:service_ref(RegisterBonjour(name, service_type, port,
+				     Callback, this)),
+	 socket_event(_loop,
+		      BIND_THIS_METHOD(OnSocketReady),
+		      SocketDescriptor(DNSServiceRefSockFD(service_ref)))
+{
+	socket_event.ScheduleRead();
+}
+
+void
+BonjourHelper::Callback([[maybe_unused]] DNSServiceRef sdRef,
+			[[maybe_unused]] DNSServiceFlags flags,
+			DNSServiceErrorType errorCode, const char *name,
+			[[maybe_unused]] const char *regtype,
+			[[maybe_unused]] const char *domain,
+			[[maybe_unused]] void *context) noexcept
+{
+	auto &helper = *(BonjourHelper *)context;
+
+	if (errorCode != kDNSServiceErr_NoError) {
+		LogError(bonjour_domain,
+			 "Failed to register zeroconf service");
+
+		helper.Cancel();
+	} else {
+		FmtDebug(bonjour_domain,
+			 "Registered zeroconf service with name {:?}",
+			 name);
+	}
+}
+
+std::unique_ptr<BonjourHelper>
+BonjourInit(EventLoop &loop, const char *name,
+	    const char *service_type, unsigned port)
+{
+	return std::make_unique<BonjourHelper>(loop, name, service_type, port);
+}

src/zeroconf/Bonjour.hxx

@@ -0,0 +1,55 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+// Copyright The Music Player Daemon Project
+
+#ifndef MPD_ZEROCONF_BONJOUR_HXX
+#define MPD_ZEROCONF_BONJOUR_HXX
+
+#include "event/SocketEvent.hxx"
+
+#include <dns_sd.h>
+
+#include <memory>
+
+class EventLoop;
+
+class BonjourHelper final {
+	const DNSServiceRef service_ref;
+
+	SocketEvent socket_event;
+
+public:
+	BonjourHelper(EventLoop &_loop, const char *name,
+		      const char *service_name, unsigned port);
+
+	~BonjourHelper() noexcept {
+		DNSServiceRefDeallocate(service_ref);
+	}
+
+	BonjourHelper(const BonjourHelper &) = delete;
+	BonjourHelper &operator=(const BonjourHelper &) = delete;
+
+private:
+	void Cancel() noexcept {
+		socket_event.Cancel();
+	}
+
+	static void Callback(DNSServiceRef sdRef, DNSServiceFlags flags,
+			     DNSServiceErrorType errorCode, const char *name,
+			     const char *regtype,
+			     const char *domain,
+			     void *context) noexcept;
+
+	/* virtual methods from class SocketMonitor */
+	void OnSocketReady([[maybe_unused]] unsigned flags) noexcept {
+		DNSServiceProcessResult(service_ref);
+	}
+};
+
+/**
+ * Throws on error.
+ */
+std::unique_ptr<BonjourHelper>
+BonjourInit(EventLoop &loop, const char *name,
+	    const char *service_type, unsigned port);
+
+#endif

src/zeroconf/Glue.cxx

@@ -3,13 +3,20 @@
 
 #include "Glue.hxx"
 #include "Helper.hxx"
-#include "avahi/Helper.hxx"
 #include "config/Data.hxx"
 #include "config/Option.hxx"
 #include "Listen.hxx"
 #include "util/Domain.hxx"
 #include "Log.hxx"
 
+#ifdef HAVE_AVAHI
+#include "avahi/Helper.hxx"
+#endif
+
+#ifdef HAVE_BONJOUR
+#include "Bonjour.hxx"
+#endif
+
 #include <climits>
 
 #include <string.h>

src/zeroconf/Glue.hxx

@@ -1,9 +1,11 @@
 // SPDX-License-Identifier: GPL-2.0-or-later
 // Copyright The Music Player Daemon Project
 
-#pragma once
+#ifndef MPD_ZEROCONF_GLUE_HXX
+#define MPD_ZEROCONF_GLUE_HXX
 
 #include "Helper.hxx"
+#include "config.h"
 
 #include <memory>
 
@@ -11,8 +13,14 @@ struct ConfigData;
 class EventLoop;
 class ZeroconfHelper;
 
+#ifdef HAVE_ZEROCONF
+
 /**
  * Throws on error.
  */
 std::unique_ptr<ZeroconfHelper>
 ZeroconfInit(const ConfigData &config, EventLoop &loop);
+
+#endif /* ! HAVE_ZEROCONF */
+
+#endif

src/zeroconf/Helper.cxx

@@ -2,10 +2,19 @@
 // Copyright The Music Player Daemon Project
 
 #include "Helper.hxx"
+
+#ifdef HAVE_AVAHI
 #include "avahi/Helper.hxx"
+#define CreateHelper AvahiInit
+#endif
+
+#ifdef HAVE_BONJOUR
+#include "Bonjour.hxx"
+#define CreateHelper BonjourInit
+#endif
 
 ZeroconfHelper::ZeroconfHelper(EventLoop &event_loop, const char *name,
 			       const char *service_type, unsigned port)
-	:helper(AvahiInit(event_loop, name, service_type, port)) {}
+	:helper(CreateHelper(event_loop, name, service_type, port)) {}
 
 ZeroconfHelper::~ZeroconfHelper() noexcept = default;

src/zeroconf/Helper.hxx

@@ -1,15 +1,25 @@
 // SPDX-License-Identifier: GPL-2.0-or-later
 // Copyright The Music Player Daemon Project
 
-#pragma once
+#ifndef MPD_ZEROCONF_HELPER_HXX
+#define MPD_ZEROCONF_HELPER_HXX
+
+#include "config.h"
 
 #include <memory>
 
 class EventLoop;
 class AvahiHelper;
+class BonjourHelper;
 
 class ZeroconfHelper final {
+#ifdef HAVE_AVAHI
 	std::unique_ptr<AvahiHelper> helper;
+#endif
+
+#ifdef HAVE_BONJOUR
+	std::unique_ptr<BonjourHelper> helper;
+#endif
 
 public:
 	ZeroconfHelper(EventLoop &event_loop, const char *name,
@@ -17,3 +27,5 @@ public:
 
 	~ZeroconfHelper() noexcept;
 };
+
+#endif

src/zeroconf/meson.build

@@ -3,7 +3,9 @@ zeroconf_option = get_option('zeroconf')
 avahi_dep = dependency('', required: false)
 
 if zeroconf_option == 'auto'
-  if is_android or is_windows
+  if is_darwin
+    zeroconf_option = 'bonjour'
+  elif is_android or is_windows
     zeroconf_option = 'disabled'
   elif dbus_dep.found()
     zeroconf_option = 'avahi'
@@ -17,30 +19,61 @@ if zeroconf_option == 'disabled'
   subdir_done()
 endif
 
-subdir('avahi')
+if zeroconf_option == 'bonjour'
+  if not compiler.has_header('dns_sd.h')
+    error('dns_sd.h not found')
+  endif
 
-if not avahi_dep.found()
-  zeroconf_dep = dependency('', required: false)
-  subdir_done()
+  bonjour_deps = [
+  ]
+
+  if not is_darwin
+    bonjour_deps += declare_dependency(link_args: ['-ldns_sd'])
+  endif
+  conf.set('HAVE_BONJOUR', true)
+
+  zeroconf = static_library(
+    'zeroconf_bonjour',
+    'Glue.cxx',
+    'Helper.cxx',
+    'Bonjour.cxx',
+    include_directories: inc,
+    dependencies: [
+      event_dep,
+      log_dep,
+    ],
+  )
+
+  zeroconf_dep = declare_dependency(
+    link_with: zeroconf,
+    dependencies: bonjour_deps,
+  )
+else
+  subdir('avahi')
+
+  if not avahi_dep.found()
+    zeroconf_dep = dependency('', required: false)
+    subdir_done()
+  endif
+
+  conf.set('HAVE_AVAHI', true)
+  
+  zeroconf = static_library(
+    'zeroconf_bonjour',
+    'Glue.cxx',
+    'Helper.cxx',
+    include_directories: inc,
+    dependencies: [
+      avahi_dep,
+      dbus_dep,
+      time_dep,
+      log_dep,
+    ],
+  )
+
+  zeroconf_dep = declare_dependency(
+    link_with: zeroconf,
+  )
 endif
 
-conf.set('HAVE_AVAHI', true)
-
-zeroconf = static_library(
-  'zeroconf',
-  'Glue.cxx',
-  'Helper.cxx',
-  include_directories: inc,
-  dependencies: [
-    avahi_dep,
-    dbus_dep,
-    time_dep,
-    log_dep,
-  ],
-)
-
-zeroconf_dep = declare_dependency(
-  link_with: zeroconf,
-)
-
 conf.set('HAVE_ZEROCONF', true)