zeroconf: add avahi zerconf discover module

Discovers remote sinks and sources and load the tunnel module to
make a local sink and source for them.

meson.build

@@ -311,6 +311,7 @@ sdl_dep = dependency('sdl2', required : get_option('sdl2'))
 ncurses_dep = dependency('ncursesw', required : false)
 sndfile_dep = dependency('sndfile', version : '>= 1.0.20', required : get_option('sndfile'))
 pulseaudio_dep = dependency('libpulse', required : get_option('libpulse'))
+avahi_dep = dependency('avahi-client', required : get_option('avahi'))
 
 gst_option = get_option('gstreamer')
 gst_deps_def = {

meson_options.txt

@@ -187,3 +187,7 @@ option('libpulse',
        description: 'Enable code that depends on libpulse',
        type: 'feature',
        value: 'auto')
+option('avahi',
+       description: 'Enable code that depends on avahi',
+       type: 'feature',
+       value: 'auto')

src/modules/meson.build

@@ -265,3 +265,16 @@ pipewire_module_session_manager = shared_library('pipewire-module-session-manage
   install_rpath: modules_install_dir,
   dependencies : [mathlib, dl_lib, pipewire_dep],
 )
+
+if avahi_dep.found()
+pipewire_module_zeroconf_discover = shared_library('pipewire-module-zeroconf-discover',
+  [ 'module-zeroconf-discover.c',
+    'module-zeroconf-discover/avahi-poll.c' ],
+  c_args : pipewire_module_c_args,
+  include_directories : [configinc, spa_inc],
+  install : true,
+  install_dir : modules_install_dir,
+  install_rpath: modules_install_dir,
+  dependencies : [mathlib, dl_lib, rt_lib, pipewire_dep, avahi_dep],
+)
+endif

src/modules/module-zeroconf-discover.c

@@ -0,0 +1,477 @@
+/* PipeWire
+ *
+ * Copyright © 2021 Wim Taymans
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+#include <string.h>
+#include <stdio.h>
+#include <errno.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+#include "config.h"
+
+#include <spa/utils/result.h>
+#include <spa/utils/json.h>
+
+#include <pipewire/impl.h>
+#include <pipewire/private.h>
+#include <pipewire/i18n.h>
+
+#include <avahi-client/lookup.h>
+#include <avahi-common/error.h>
+#include <avahi-common/malloc.h>
+
+#include "module-zeroconf-discover/avahi-poll.h"
+
+#define NAME "zeroconf-discover"
+
+#define MODULE_USAGE	" "
+
+static const struct spa_dict_item module_props[] = {
+	{ PW_KEY_MODULE_AUTHOR, "Wim Taymans <wim.taymans@gmail.com>" },
+	{ PW_KEY_MODULE_DESCRIPTION, "Discover remote streams" },
+	{ PW_KEY_MODULE_USAGE, MODULE_USAGE },
+	{ PW_KEY_MODULE_VERSION, PACKAGE_VERSION },
+};
+
+#define SERVICE_TYPE_SINK "_pulse-sink._tcp"
+#define SERVICE_TYPE_SOURCE "_non-monitor._sub._pulse-source._tcp"
+
+
+struct impl {
+	struct pw_context *context;
+
+	struct pw_impl_module *module;
+	struct spa_hook module_listener;
+	struct pw_work_queue *work;
+
+	struct pw_properties *properties;
+
+	AvahiPoll *avahi_poll;
+	AvahiClient *client;
+	AvahiServiceBrowser *sink_browser;
+	AvahiServiceBrowser *source_browser;
+
+	struct spa_list tunnel_list;
+
+	unsigned int unloading:1;
+};
+
+struct tunnel_info {
+	AvahiIfIndex interface;
+	AvahiProtocol protocol;
+	const char *name;
+	const char *type;
+	const char *domain;
+};
+
+#define TUNNEL_INFO(...) (struct tunnel_info){ __VA_ARGS__ }
+
+struct tunnel {
+	struct spa_list link;
+	struct tunnel_info info;
+	struct pw_impl_module *module;
+	struct spa_hook module_listener;
+};
+
+static int start_client(struct impl *impl);
+
+static void do_unload_module(void *obj, void *data, int res, uint32_t id)
+{
+	struct impl *impl = data;
+	pw_impl_module_destroy(impl->module);
+}
+
+static void unload_module(struct impl *impl)
+{
+	if (!impl->unloading) {
+		impl->unloading = true;
+		pw_work_queue_add(impl->work, impl, 0, do_unload_module, impl);
+	}
+}
+
+static void module_destroy(void *data)
+{
+	struct impl *impl = data;
+
+	spa_hook_remove(&impl->module_listener);
+
+	if (impl->properties)
+		pw_properties_free(impl->properties);
+
+	free(impl);
+}
+
+static const struct pw_impl_module_events module_events = {
+	PW_VERSION_IMPL_MODULE_EVENTS,
+	.destroy = module_destroy,
+};
+
+static struct tunnel *make_tunnel(struct impl *impl, const struct tunnel_info *info)
+{
+	struct tunnel *t;
+
+	t = calloc(1, sizeof(*t));
+	if (t == NULL)
+		return NULL;
+
+	t->info.interface = info->interface;
+	t->info.protocol = info->protocol;
+	t->info.name = strdup(info->name);
+	t->info.type = strdup(info->type);
+	t->info.domain = strdup(info->domain);
+	spa_list_append(&impl->tunnel_list, &t->link);
+
+	return t;
+}
+
+static struct tunnel *find_tunnel(struct impl *impl, const struct tunnel_info *info)
+{
+	struct tunnel *t;
+	spa_list_for_each(t, &impl->tunnel_list, link) {
+		if (t->info.interface == info->interface &&
+		    t->info.protocol == info->protocol &&
+		    strcmp(t->info.name, info->name) == 0 &&
+		    strcmp(t->info.type, info->type) == 0 &&
+		    strcmp(t->info.domain, info->domain) == 0)
+			return t;
+	}
+	return NULL;
+}
+
+static void free_tunnel(struct tunnel *t)
+{
+	spa_list_remove(&t->link);
+	if (t->module)
+		pw_impl_module_destroy(t->module);
+	free((char*)t->info.name);
+	free((char*)t->info.type);
+	free((char*)t->info.domain);
+	free(t);
+}
+
+static void serialize_dict(FILE *f, const struct spa_dict *dict)
+{
+	const struct spa_dict_item *it;
+	spa_dict_for_each(it, dict) {
+		size_t len = it->value ? strlen(it->value) : 0;
+		fprintf(f, " \"%s\" = ", it->key);
+		if (it->value == NULL) {
+			fprintf(f, "null");
+		} else if (spa_json_is_null(it->value, len) ||
+		    spa_json_is_float(it->value, len) ||
+		    spa_json_is_bool(it->value, len) ||
+		    spa_json_is_container(it->value, len)) {
+			fprintf(f, "%s", it->value);
+		} else {
+			size_t size = (len+1) * 4;
+			char str[size];
+			spa_json_encode_string(str, size, it->value);
+			fprintf(f, "%s", str);
+		}
+	}
+}
+
+static void resolver_cb(AvahiServiceResolver *r, AvahiIfIndex interface, AvahiProtocol protocol,
+	AvahiResolverEvent event, const char *name, const char *type, const char *domain,
+	const char *host_name, const AvahiAddress *a, uint16_t port, AvahiStringList *txt,
+	AvahiLookupResultFlags flags, void *userdata)
+{
+	struct impl *impl = userdata;
+	struct tunnel *t;
+	struct tunnel_info tinfo;
+	const char *str, *device;
+	char if_suffix[16] = "";
+	char at[AVAHI_ADDRESS_STR_MAX];
+	AvahiStringList *l;
+	FILE *f;
+	char *args;
+	size_t size;
+	struct pw_impl_module *mod;
+	struct pw_properties *props = NULL;
+
+	if (event != AVAHI_RESOLVER_FOUND) {
+		pw_log_error("Resolving of '%s' failed: %s", name,
+				avahi_strerror(avahi_client_errno(impl->client)));
+		return;
+	}
+
+	props = pw_properties_new(NULL, NULL);
+	if (props == NULL) {
+		pw_log_error("Can't allocate properties: %m");
+		return;
+	}
+
+	tinfo = TUNNEL_INFO(.interface = interface,
+			.protocol = protocol,
+			.name = name,
+			.type = type,
+			.domain = domain);
+
+	for (l = txt; l; l = l->next) {
+		char *key, *value;
+
+		if (avahi_string_list_get_pair(l, &key, &value, NULL) != 0)
+			break;
+
+		if (strcmp(key, "device") == 0) {
+			pw_properties_set(props, "node.target", value);
+		}
+		else if (strcmp(key, "rate") == 0) {
+			pw_properties_setf(props, "audio.rate", "%u", atoi(value));
+		}
+		else if (strcmp(key, "channels") == 0) {
+			pw_properties_setf(props, "audio.channels", "%u", atoi(value));
+		}
+		else if (strcmp(key, "format") == 0) {
+			pw_properties_set(props, "audio.format", value);
+		}
+		else if (strcmp(key, "icon-name") == 0) {
+			pw_properties_set(props, "device.icon-name", value);
+		}
+		else if (strcmp(key, "channel_map") == 0) {
+		}
+		avahi_free(key);
+		avahi_free(value);
+	}
+
+	if ((device = pw_properties_get(props, "node.target")) != NULL)
+		pw_properties_setf(props, "node.name",
+				"tunnel.%s.%s", host_name, device);
+	else
+		pw_properties_setf(props, "node.name",
+				"tunnel.%s", host_name);
+
+
+	str = strstr(type, "sink") ? "playback" : "capture";
+	pw_properties_set(props, "tunnel.mode", str);
+
+	if (a->proto == AVAHI_PROTO_INET6 &&
+	    a->data.ipv6.address[0] == 0xfe &&
+	    (a->data.ipv6.address[1] & 0xc0) == 0x80)
+		snprintf(if_suffix, sizeof(if_suffix), "%%%d", interface);
+
+	pw_properties_setf(props, "pulse.server.address", "[%s%s]:%u",
+			avahi_address_snprint(at, sizeof(at), a),
+			if_suffix, port);
+
+	if ((str = pw_properties_get(props, "pulse.server.address")) != NULL)
+		pw_properties_setf(props, "node.description",
+				_("Tunnel to %s/%s"), str, device);
+
+	f = open_memstream(&args, &size);
+	fprintf(f, "{");
+	serialize_dict(f, &props->dict);
+	fprintf(f, " stream.props = {");
+	fprintf(f, " }");
+	fprintf(f, "}");
+        fclose(f);
+
+	pw_properties_free(props);
+
+	mod = pw_context_load_module(impl->context,
+			"libpipewire-module-pulse-tunnel",
+			args, NULL);
+	free(args);
+
+	if (mod == NULL) {
+		pw_log_error("Can't load module: %m");
+                return;
+	}
+
+	t = make_tunnel(impl, &tinfo);
+	if (t == NULL)
+		return;
+
+	t->module = mod;
+}
+
+
+static void browser_cb(AvahiServiceBrowser *b, AvahiIfIndex interface, AvahiProtocol protocol,
+	AvahiBrowserEvent event, const char *name, const char *type, const char *domain,
+	AvahiLookupResultFlags flags, void *userdata)
+{
+	struct impl *impl = userdata;
+	struct tunnel_info info;
+	struct tunnel *t;
+
+	if (flags & AVAHI_LOOKUP_RESULT_LOCAL)
+		return;
+
+	info = TUNNEL_INFO(.interface = interface,
+			.protocol = protocol,
+			.name = name,
+			.type = type,
+			.domain = domain);
+
+	t = find_tunnel(impl, &info);
+
+	switch (event) {
+	case AVAHI_BROWSER_NEW:
+		if (t != NULL)
+			return;
+		if (!(avahi_service_resolver_new(impl->client,
+						interface, protocol,
+						name, type, domain,
+						AVAHI_PROTO_UNSPEC, 0,
+						resolver_cb, impl)))
+			pw_log_error("can't make service resolver: %s",
+					avahi_strerror(avahi_client_errno(impl->client)));
+		break;
+	case AVAHI_BROWSER_REMOVE:
+		if (t == NULL)
+			return;
+		free_tunnel(t);
+		break;
+	default:
+		break;
+	}
+}
+
+
+static struct AvahiServiceBrowser *make_browser(struct impl *impl, const char *service_type)
+{
+	struct AvahiServiceBrowser *s;
+
+	s = avahi_service_browser_new(impl->client,
+                              AVAHI_IF_UNSPEC, AVAHI_PROTO_UNSPEC,
+                              service_type, NULL, 0,
+                              browser_cb, impl);
+	if (s == NULL) {
+		pw_log_error("can't make browser for %s: %s", service_type,
+				avahi_strerror(avahi_client_errno(impl->client)));
+	}
+	return s;
+}
+
+static void client_callback(AvahiClient *c, AvahiClientState state, void *userdata)
+{
+	struct impl *impl = userdata;
+
+	impl->client = c;
+
+	switch (state) {
+	case AVAHI_CLIENT_S_REGISTERING:
+	case AVAHI_CLIENT_S_RUNNING:
+	case AVAHI_CLIENT_S_COLLISION:
+		if (impl->sink_browser == NULL)
+			impl->sink_browser = make_browser(impl, SERVICE_TYPE_SINK);
+		if (impl->sink_browser == NULL)
+			goto error;
+
+		if (impl->source_browser == NULL)
+			impl->source_browser = make_browser(impl, SERVICE_TYPE_SOURCE);
+		if (impl->source_browser == NULL)
+			goto error;
+
+		break;
+	case AVAHI_CLIENT_FAILURE:
+		if (avahi_client_errno(c) == AVAHI_ERR_DISCONNECTED)
+			start_client(impl);
+
+		SPA_FALLTHROUGH;
+	case AVAHI_CLIENT_CONNECTING:
+		if (impl->sink_browser) {
+			avahi_service_browser_free(impl->sink_browser);
+			impl->sink_browser = NULL;
+		}
+		if (impl->source_browser) {
+			avahi_service_browser_free(impl->source_browser);
+			impl->source_browser = NULL;
+		}
+		break;
+	default:
+		break;
+	}
+	return;
+error:
+	unload_module(impl);
+}
+
+static int start_client(struct impl *impl)
+{
+	int res;
+	if ((impl->client = avahi_client_new(impl->avahi_poll,
+					AVAHI_CLIENT_NO_FAIL,
+					client_callback, impl,
+					&res)) == NULL) {
+		pw_log_error("can't create client: %s", avahi_strerror(res));
+		unload_module(impl);
+		return -EIO;
+	}
+	return 0;
+}
+
+static int start_avahi(struct impl *impl)
+{
+	struct pw_loop *loop;
+
+	loop = pw_context_get_main_loop(impl->context);
+	impl->avahi_poll = pw_avahi_poll_new(loop);
+
+	return start_client(impl);;
+}
+
+SPA_EXPORT
+int pipewire__module_init(struct pw_impl_module *module, const char *args)
+{
+	struct pw_context *context = pw_impl_module_get_context(module);
+	struct pw_properties *props;
+	struct impl *impl;
+	int res;
+
+	impl = calloc(1, sizeof(struct impl));
+	if (impl == NULL)
+		goto error_errno;
+
+	pw_log_debug("module %p: new %s", impl, args);
+
+	if (args)
+		args = "";
+
+	props = pw_properties_new_string(args);
+	if (props == NULL)
+		goto error_errno;
+
+	spa_list_init(&impl->tunnel_list);
+
+	impl->module = module;
+	impl->context = context;
+	impl->work = pw_context_get_work_queue(context);
+	impl->properties = props;
+
+	pw_impl_module_add_listener(module, &impl->module_listener, &module_events, impl);
+
+	pw_impl_module_update_properties(module, &SPA_DICT_INIT_ARRAY(module_props));
+
+	start_avahi(impl);
+
+	return 0;
+
+error_errno:
+	res = -errno;
+	free(impl);
+	return res;
+}

src/modules/module-zeroconf-discover/avahi-poll.c

@@ -0,0 +1,191 @@
+/* PipeWire
+ *
+ * Copyright © 2021 Wim Taymans
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+#include <pipewire/pipewire.h>
+
+#include "avahi-poll.h"
+
+struct impl {
+	AvahiPoll api;
+	struct pw_loop *loop;
+};
+
+struct AvahiWatch {
+	struct impl *impl;
+	struct spa_source *source;
+	AvahiWatchEvent events;
+	AvahiWatchCallback callback;
+	void *userdata;
+};
+
+struct AvahiTimeout {
+	struct impl *impl;
+	struct spa_source *source;
+	AvahiTimeoutCallback callback;
+	void *userdata;
+};
+
+static AvahiWatchEvent from_pw_events(uint32_t mask)
+{
+	return (mask & SPA_IO_IN ? AVAHI_WATCH_IN : 0) |
+		(mask & SPA_IO_OUT ? AVAHI_WATCH_OUT : 0) |
+		(mask & SPA_IO_ERR ? AVAHI_WATCH_ERR : 0) |
+		(mask & SPA_IO_HUP ? AVAHI_WATCH_HUP : 0);
+}
+
+static uint32_t to_pw_events(AvahiWatchEvent e) {
+	return (e & AVAHI_WATCH_IN ? SPA_IO_IN : 0) |
+		(e & AVAHI_WATCH_OUT ? SPA_IO_OUT : 0) |
+		(e & AVAHI_WATCH_ERR ? SPA_IO_ERR : 0) |
+		(e & AVAHI_WATCH_HUP ? SPA_IO_HUP : 0);
+}
+
+static void watch_callback(void *data, int fd, uint32_t mask)
+{
+	AvahiWatch *w = data;
+
+	w->events = from_pw_events(mask);
+	w->callback(w, fd, w->events, w->userdata);
+	w->events = 0;
+}
+
+static AvahiWatch* watch_new(const AvahiPoll *api, int fd, AvahiWatchEvent event,
+		AvahiWatchCallback callback, void *userdata)
+{
+	struct impl *impl = api->userdata;
+	AvahiWatch *w;
+
+	w = calloc(1, sizeof(*w));
+	if (w == NULL)
+		return NULL;
+
+	w->impl = impl;
+	w->events = 0;
+	w->callback = callback;
+	w->userdata = userdata;
+	w->source = pw_loop_add_io(impl->loop, fd, to_pw_events(event),
+			false, watch_callback, w);
+
+	return w;
+}
+
+static void watch_update(AvahiWatch *w, AvahiWatchEvent event)
+{
+	struct impl *impl = w->impl;
+	pw_loop_update_io(impl->loop, w->source, to_pw_events(event));
+}
+
+static AvahiWatchEvent watch_get_events(AvahiWatch *w)
+{
+	return w->events;
+}
+
+static void watch_free(AvahiWatch *w)
+{
+	struct impl *impl = w->impl;
+	pw_loop_destroy_source(impl->loop, w->source);
+	free(w);
+}
+
+static void timeout_callback(void *data, uint64_t expirations)
+{
+	AvahiTimeout *w = data;
+	w->callback(w, w->userdata);
+}
+
+static AvahiTimeout* timeout_new(const AvahiPoll *api, const struct timeval *tv,
+		AvahiTimeoutCallback callback, void *userdata)
+{
+	struct impl *impl = api->userdata;
+	struct timespec value;
+	AvahiTimeout *w;
+
+	w = calloc(1, sizeof(*w));
+	if (w == NULL)
+		return NULL;
+
+	w->impl = impl;
+	w->callback = callback;
+	w->userdata = userdata;
+	w->source = pw_loop_add_timer(impl->loop, timeout_callback, w);
+
+	if (tv != NULL) {
+		value.tv_sec = tv->tv_sec;
+		value.tv_nsec = tv->tv_usec * 1000UL;
+		pw_loop_update_timer(impl->loop, w->source, &value, NULL, true);
+	}
+	return w;
+}
+
+static void timeout_update(AvahiTimeout *t, const struct timeval *tv)
+{
+	struct impl *impl = t->impl;
+	struct timespec value, *v = NULL;
+
+	if (tv != NULL) {
+		value.tv_sec = tv->tv_sec;
+		value.tv_nsec = tv->tv_usec * 1000UL;
+		if (value.tv_sec == 0 && value.tv_nsec == 0)
+			value.tv_nsec = 1;
+		v = &value;
+	}
+	pw_loop_update_timer(impl->loop, t->source, v, NULL, true);
+}
+
+static void timeout_free(AvahiTimeout *t)
+{
+	struct impl *impl = t->impl;
+	pw_loop_destroy_source(impl->loop, t->source);
+	free(t);
+}
+
+static const AvahiPoll avahi_poll_api = {
+	.watch_new = watch_new,
+	.watch_update = watch_update,
+	.watch_get_events = watch_get_events,
+	.watch_free = watch_free,
+	.timeout_new = timeout_new,
+	.timeout_update = timeout_update,
+	.timeout_free = timeout_free,
+};
+
+AvahiPoll* pw_avahi_poll_new(struct pw_loop *loop)
+{
+	struct impl *impl;
+
+	impl = calloc(1, sizeof(*impl));
+	if (impl == NULL)
+		return NULL;
+
+	impl->loop = loop;
+	impl->api = avahi_poll_api;
+	impl->api.userdata = impl;
+
+	return &impl->api;
+}
+
+void pw_avahi_poll_free(AvahiPoll *p)
+{
+	free(p);
+}

src/modules/module-zeroconf-discover/avahi-poll.h

@@ -0,0 +1,31 @@
+/* PipeWire
+ *
+ * Copyright © 2021 Wim Taymans
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+#include <avahi-client/client.h>
+
+#include <pipewire/loop.h>
+
+AvahiPoll* pw_avahi_poll_new(struct pw_loop *loop);
+
+void pw_avahi_poll_free(AvahiPoll *p);