1 files changed, 209 insertions, 0 deletions
diff --git a/sd/source/ui/remotecontrol/AvahiNetworkService.cxx b/sd/source/ui/remotecontrol/AvahiNetworkService.cxx
new file mode 100644
index 0000000000..7708e6eb7d
--- /dev/null
+++ b/sd/source/ui/remotecontrol/AvahiNetworkService.cxx
@@ -0,0 +1,209 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4; fill-column: 100 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+#include <config_dbus.h>
+
+#include <iostream>
+#include <limits>
+#include <new>
+#include <assert.h>
+
+#include <avahi-client/client.h>
+#include <avahi-client/publish.h>
+
+#include <avahi-common/alternative.h>
+#include <avahi-common/error.h>
+#include <avahi-common/thread-watch.h>
+#include <comphelper/random.hxx>
+
+#if ENABLE_DBUS
+#include <dbus/dbus.h>
+#endif
+
+#include <sal/log.hxx>
+
+#include "AvahiNetworkService.hxx"
+#include "ZeroconfService.hxx"
+
+using namespace sd;
+
+static AvahiClient *client = nullptr;
+static AvahiThreadedPoll *threaded_poll = nullptr;
+static AvahiEntryGroup *group = nullptr;
+static AvahiNetworkService *avahiService = nullptr;
+
+static bool create_services(AvahiClient *c);
+
+static void entry_group_callback(AvahiEntryGroup *g, AvahiEntryGroupState state, AVAHI_GCC_UNUSED void *userdata) {
+    assert(g == group || group == nullptr);
+    group = g;
+
+    /* Called whenever the entry group state changes */
+
+    switch (state) {
+        case AVAHI_ENTRY_GROUP_ESTABLISHED :
+            /* The entry group has been established successfully */
+            SAL_INFO( "sdremote.wifi", "Service '" << avahiService->getName() << "' successfully established." );
+            break;
+
+        case AVAHI_ENTRY_GROUP_COLLISION : {
+            char *n;
+
+            /* A service name collision with a remote service
+             * happened. Let's pick a new name */
+            n = avahi_alternative_service_name(avahiService->getName().c_str());
+            avahiService->setName(n);
+
+            SAL_INFO( "sdremote.wifi", "Service name collision, renaming service to '" << avahiService->getName() << "'");
+
+            /* And recreate the services */
+            create_services(avahi_entry_group_get_client(g));
+            break;
+        }
+
+        case AVAHI_ENTRY_GROUP_FAILURE :
+
+            SAL_WARN("sdremote.wifi", "Entry group failure: " << avahi_strerror(avahi_client_errno(avahi_entry_group_get_client(g))));
+
+            /* Some kind of failure happened while we were registering our services */
+            avahi_threaded_poll_quit(threaded_poll);
+            break;
+
+        case AVAHI_ENTRY_GROUP_UNCOMMITED:
+        case AVAHI_ENTRY_GROUP_REGISTERING:
+            ;
+    }
+}
+
+static bool create_services(AvahiClient *c) {
+    assert(c);
+
+    /* If this is the first time we're called, let's create a new
+     * entry group if necessary */
+    if(!client)
+        return false;
+
+    if (!group)
+        if (!(group = avahi_entry_group_new(c, entry_group_callback, nullptr))) {
+            SAL_WARN("sdremote.wifi", "avahi_entry_group_new() failed: " << avahi_strerror(avahi_client_errno(c)));
+            avahiService->clear();
+            return false;
+        }
+
+    /* If the group is empty (either because it was just created, or
+     * because it was reset previously, add our entries.  */
+
+    if (avahi_entry_group_is_empty(group)) {
+        SAL_INFO("sdremote.wifi", "Adding service '" << avahiService->getName() << "'");
+        char r[128];
+        int nRandom = comphelper::rng::uniform_int_distribution(0, std::numeric_limits<int>::max());
+        snprintf(r, sizeof(r), "random=%i", nRandom);
+        int ret = avahi_entry_group_add_service(
+            group, AVAHI_IF_UNSPEC, AVAHI_PROTO_UNSPEC, static_cast<AvahiPublishFlags>(0),
+            avahiService->getName().c_str(), kREG_TYPE, nullptr, nullptr, 1599, "local", r, nullptr
+        );
+        if (ret < 0) {
+
+            if (ret == AVAHI_ERR_COLLISION){
+                /* A service name collision with a local service happened. Let's
+                 * pick a new name */
+                char *n = avahi_alternative_service_name(avahiService->getName().c_str());
+                avahiService->setName(n);
+
+                SAL_WARN("sdremote.wifi", "Service name collision, renaming service to '" << avahiService->getName() << "'");
+
+                avahi_entry_group_reset(group);
+
+                return create_services(c);
+            }
+
+            SAL_WARN("sdremote.wifi", "Failed to add _impressremote._tcp service: " << avahi_strerror(ret));
+            avahiService->clear();
+            return false;
+        }
+
+        /* Tell the server to register the service */
+        if ((ret = avahi_entry_group_commit(group)) < 0) {
+            SAL_WARN("sdremote.wifi", "Failed to commit entry group: " << avahi_strerror(ret));
+            avahiService->clear();
+            return false;
+        }
+    }
+
+    return true; //Services we're already created
+}
+
+static void client_callback(AvahiClient *c, AvahiClientState state, AVAHI_GCC_UNUSED void * userdata) {
+    assert(c);
+
+    /* Called whenever the client or server state changes */
+
+    switch (state) {
+        case AVAHI_CLIENT_S_RUNNING:
+            create_services(c);
+            break;
+        case AVAHI_CLIENT_FAILURE:
+            SAL_WARN("sdremote.wifi", "Client failure: " << avahi_strerror(avahi_client_errno(c)));
+            avahiService->clear();
+            break;
+        case AVAHI_CLIENT_S_COLLISION:
+        case AVAHI_CLIENT_S_REGISTERING:
+            if (group)
+                avahi_entry_group_reset(group);
+            break;
+        case AVAHI_CLIENT_CONNECTING:
+            ;
+    }
+}
+
+void AvahiNetworkService::setup() {
+#if ENABLE_DBUS
+    // Sure, without ENABLE_DBUS it probably makes no sense to try to use this Avahi stuff either,
+    // but this is just a stop-gap measure to get this to even compile for now with the probably
+    // pointless combination of configurable options --enable-avahi --enable-dbus --disable-gui.
+
+    // Avahi internally uses D-Bus, which requires the following in order to be
+    // thread-safe (and we potentially access D-Bus from different threads in
+    // different places of the code base):
+    if (!dbus_threads_init_default()) {
+        throw std::bad_alloc();
+    }
+#endif
+
+    int error = 0;
+    avahiService = this;
+    if (!(threaded_poll = avahi_threaded_poll_new())) {
+       SAL_WARN("sdremote.wifi", "avahi_threaded_poll_new '" << avahiService->getName() << "' failed");
+       return;
+    }
+
+    if (!(client = avahi_client_new(avahi_threaded_poll_get(threaded_poll), static_cast<AvahiClientFlags>(0), client_callback, nullptr, &error))) {
+       SAL_WARN("sdremote.wifi", "avahi_client_new failed");
+       return;
+    }
+
+    if(!create_services(client))
+        return;
+
+    /* Finally, start the event loop thread */
+    if (avahi_threaded_poll_start(threaded_poll) < 0) {
+       SAL_WARN("sdremote.wifi", "avahi_threaded_poll_start failed");
+       return;
+    }
+}
+
+void AvahiNetworkService::clear() {
+    /* Call this when the app shuts down */
+        if(threaded_poll)
+            avahi_threaded_poll_stop(threaded_poll);
+        if(client)
+            avahi_client_free(client);
+        if(threaded_poll)
+            avahi_threaded_poll_free(threaded_poll);
+}