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/* -*- 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);
}
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