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Diffstat (limited to 'src/zeroconf/ZeroconfAvahi.cxx')
-rw-r--r-- | src/zeroconf/ZeroconfAvahi.cxx | 282 |
1 files changed, 282 insertions, 0 deletions
diff --git a/src/zeroconf/ZeroconfAvahi.cxx b/src/zeroconf/ZeroconfAvahi.cxx new file mode 100644 index 000000000..5adda38f9 --- /dev/null +++ b/src/zeroconf/ZeroconfAvahi.cxx @@ -0,0 +1,282 @@ +/* + * Copyright (C) 2003-2014 The Music Player Daemon Project + * http://www.musicpd.org + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + */ + +#include "config.h" +#include "ZeroconfAvahi.hxx" +#include "AvahiPoll.hxx" +#include "ZeroconfInternal.hxx" +#include "Listen.hxx" +#include "system/FatalError.hxx" +#include "util/Domain.hxx" +#include "Log.hxx" + +#include <avahi-client/client.h> +#include <avahi-client/publish.h> + +#include <avahi-common/alternative.h> +#include <avahi-common/domain.h> +#include <avahi-common/malloc.h> +#include <avahi-common/error.h> + +#include <dbus/dbus.h> + +static constexpr Domain avahi_domain("avahi"); + +static char *avahi_name; +static MyAvahiPoll *avahi_poll; +static AvahiClient *avahi_client; +static AvahiEntryGroup *avahi_group; + +static void +AvahiRegisterService(AvahiClient *c); + +/** + * Callback when the EntryGroup changes state. + */ +static void +AvahiGroupCallback(AvahiEntryGroup *g, + AvahiEntryGroupState state, + gcc_unused void *userdata) +{ + assert(g != nullptr); + + FormatDebug(avahi_domain, + "Service group changed to state %d", state); + + switch (state) { + case AVAHI_ENTRY_GROUP_ESTABLISHED: + /* The entry group has been established successfully */ + FormatDefault(avahi_domain, + "Service '%s' successfully established.", + avahi_name); + break; + + case AVAHI_ENTRY_GROUP_COLLISION: + /* A service name collision happened. Let's pick a new name */ + { + char *n = avahi_alternative_service_name(avahi_name); + avahi_free(avahi_name); + avahi_name = n; + } + + FormatDefault(avahi_domain, + "Service name collision, renaming service to '%s'", + avahi_name); + + /* And recreate the services */ + AvahiRegisterService(avahi_entry_group_get_client(g)); + break; + + case AVAHI_ENTRY_GROUP_FAILURE: + FormatError(avahi_domain, + "Entry group failure: %s", + avahi_strerror(avahi_client_errno(avahi_entry_group_get_client(g)))); + /* Some kind of failure happened while we were + registering our services */ + break; + + case AVAHI_ENTRY_GROUP_UNCOMMITED: + LogDebug(avahi_domain, "Service group is UNCOMMITED"); + break; + + case AVAHI_ENTRY_GROUP_REGISTERING: + LogDebug(avahi_domain, "Service group is REGISTERING"); + } +} + +/** + * Registers a new service with avahi. + */ +static void +AvahiRegisterService(AvahiClient *c) +{ + assert(c != nullptr); + + FormatDebug(avahi_domain, "Registering service %s/%s", + SERVICE_TYPE, avahi_name); + + /* If this is the first time we're called, + * let's create a new entry group */ + if (!avahi_group) { + avahi_group = avahi_entry_group_new(c, AvahiGroupCallback, nullptr); + if (!avahi_group) { + FormatError(avahi_domain, + "Failed to create avahi EntryGroup: %s", + avahi_strerror(avahi_client_errno(c))); + return; + } + } + + /* Add the service */ + /* TODO: This currently binds to ALL interfaces. + * We could maybe add a service per actual bound interface, + * if that's better. */ + int result = avahi_entry_group_add_service(avahi_group, + AVAHI_IF_UNSPEC, + AVAHI_PROTO_UNSPEC, + AvahiPublishFlags(0), + avahi_name, SERVICE_TYPE, + nullptr, nullptr, + listen_port, nullptr); + if (result < 0) { + FormatError(avahi_domain, "Failed to add service %s: %s", + SERVICE_TYPE, avahi_strerror(result)); + return; + } + + /* Tell the server to register the service group */ + result = avahi_entry_group_commit(avahi_group); + if (result < 0) { + FormatError(avahi_domain, "Failed to commit service group: %s", + avahi_strerror(result)); + return; + } +} + +/* Callback when avahi changes state */ +static void +MyAvahiClientCallback(AvahiClient *c, AvahiClientState state, + gcc_unused void *userdata) +{ + assert(c != nullptr); + + /* Called whenever the client or server state changes */ + FormatDebug(avahi_domain, "Client changed to state %d", state); + + switch (state) { + int reason; + + case AVAHI_CLIENT_S_RUNNING: + LogDebug(avahi_domain, "Client is RUNNING"); + + /* The server has startup successfully and registered its host + * name on the network, so it's time to create our services */ + if (avahi_group == nullptr) + AvahiRegisterService(c); + break; + + case AVAHI_CLIENT_FAILURE: + reason = avahi_client_errno(c); + if (reason == AVAHI_ERR_DISCONNECTED) { + LogDefault(avahi_domain, + "Client Disconnected, will reconnect shortly"); + if (avahi_group != nullptr) { + avahi_entry_group_free(avahi_group); + avahi_group = nullptr; + } + + if (avahi_client != nullptr) + avahi_client_free(avahi_client); + avahi_client = + avahi_client_new(avahi_poll, + AVAHI_CLIENT_NO_FAIL, + MyAvahiClientCallback, nullptr, + &reason); + if (avahi_client == nullptr) + FormatWarning(avahi_domain, + "Could not reconnect: %s", + avahi_strerror(reason)); + } else { + FormatWarning(avahi_domain, + "Client failure: %s (terminal)", + avahi_strerror(reason)); + } + + break; + + case AVAHI_CLIENT_S_COLLISION: + LogDebug(avahi_domain, "Client is COLLISION"); + + /* Let's drop our registered services. When the server + is back in AVAHI_SERVER_RUNNING state we will + register them again with the new host name. */ + if (avahi_group != nullptr) { + LogDebug(avahi_domain, "Resetting group"); + avahi_entry_group_reset(avahi_group); + } + + break; + + case AVAHI_CLIENT_S_REGISTERING: + LogDebug(avahi_domain, "Client is REGISTERING"); + + /* The server records are now being established. This + * might be caused by a host name change. We need to wait + * for our own records to register until the host name is + * properly esatblished. */ + + if (avahi_group != nullptr) { + LogDebug(avahi_domain, "Resetting group"); + avahi_entry_group_reset(avahi_group); + } + + break; + + case AVAHI_CLIENT_CONNECTING: + LogDebug(avahi_domain, "Client is CONNECTING"); + break; + } +} + +void +AvahiInit(EventLoop &loop, const char *serviceName) +{ + LogDebug(avahi_domain, "Initializing interface"); + + if (!avahi_is_valid_service_name(serviceName)) + FormatFatalError("Invalid zeroconf_name \"%s\"", serviceName); + + avahi_name = avahi_strdup(serviceName); + + avahi_poll = new MyAvahiPoll(loop); + + int error; + avahi_client = avahi_client_new(avahi_poll, AVAHI_CLIENT_NO_FAIL, + MyAvahiClientCallback, nullptr, + &error); + if (avahi_client == nullptr) { + FormatError(avahi_domain, "Failed to create client: %s", + avahi_strerror(error)); + AvahiDeinit(); + } +} + +void +AvahiDeinit() +{ + LogDebug(avahi_domain, "Shutting down interface"); + + if (avahi_group != nullptr) { + avahi_entry_group_free(avahi_group); + avahi_group = nullptr; + } + + if (avahi_client != nullptr) { + avahi_client_free(avahi_client); + avahi_client = nullptr; + } + + delete avahi_poll; + avahi_poll = nullptr; + + avahi_free(avahi_name); + avahi_name = nullptr; + + dbus_shutdown(); +} |