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.

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);