--- /dev/null
+/* GStreamer
+ * Copyright (C) 2019 Mathieu Duponchelle <mathieu@centricular.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#include <microdns/microdns.h>
+
+#include "gstmicrodnsdevice.h"
+
+typedef struct _ListenerContext ListenerContext;
+
+struct _GstMDNSDeviceProvider
+{
+ GstDeviceProvider parent;
+ ListenerContext *current_ctx;
+};
+
+#define LISTEN_INTERVAL_SECONDS 2
+
+/* #GstDeviceProvider.stop() is synchronous, but libmicrodns' stop mechanism
+ * isn't, as it polls and queries the application's provided stop function
+ * before each new loop crank. This means there can potentially exist N
+ * contexts at any given time, if the provider is started and stopped in
+ * rapid succession. At most one of them can be active however (stop == false),
+ * with the other N - 1 in the process of stopping (stop == true).
+ *
+ * Additionally, mdns_listen() is a blocking call, thus the need to run it in
+ * its own thread.
+ */
+struct _ListenerContext
+{
+ GMutex lock;
+ GstDeviceProvider *provider;
+
+ /* The following fields are protected by @lock */
+ bool stop;
+ GHashTable *devices;
+ GSequence *last_seen_devices;
+};
+
+G_DEFINE_TYPE (GstMDNSDeviceProvider, gst_mdns_device_provider,
+ GST_TYPE_DEVICE_PROVIDER);
+
+struct _GstMDNSDevice
+{
+ GstDevice parent;
+
+ GstURIType uri_type;
+ gchar *uri;
+ GSequenceIter *iter;
+ gint64 last_seen;
+};
+
+G_DEFINE_TYPE (GstMDNSDevice, gst_mdns_device, GST_TYPE_DEVICE);
+
+static gint
+cmp_last_seen (GstMDNSDevice * a, GstMDNSDevice * b,
+ gpointer G_GNUC_UNUSED user_data)
+{
+ if (a->last_seen < b->last_seen)
+ return -1;
+ if (a->last_seen == b->last_seen)
+ return 0;
+ return 1;
+}
+
+static gint
+cmp_last_seen_iter (GSequenceIter * ia, GSequenceIter * ib, gpointer user_data)
+{
+ return cmp_last_seen (GST_MDNS_DEVICE (g_sequence_get (ia)),
+ GST_MDNS_DEVICE (g_sequence_get (ib)), user_data);
+}
+
+static void
+gst_mdns_device_finalize (GObject * object)
+{
+ GstMDNSDevice *self = GST_MDNS_DEVICE (object);
+
+ g_free (self->uri);
+
+ G_OBJECT_CLASS (gst_mdns_device_parent_class)->finalize (object);
+}
+
+static GstElement *
+gst_mdns_device_create_element (GstDevice * device, const gchar * name)
+{
+ GstMDNSDevice *self = GST_MDNS_DEVICE (device);
+ GstElement *ret;
+ GError *err = NULL;
+
+ ret = gst_element_make_from_uri (self->uri_type, self->uri, name, &err);
+
+ if (!ret) {
+ GST_ERROR_OBJECT (self, "Failed to create element for URI %s: %s",
+ self->uri, err->message);
+ g_clear_error (&err);
+ }
+
+ return ret;
+}
+
+static void
+gst_mdns_device_init (GstMDNSDevice * self)
+{
+}
+
+static void
+gst_mdns_device_class_init (GstMDNSDeviceClass * klass)
+{
+ GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
+ GstDeviceClass *gst_device_class = GST_DEVICE_CLASS (klass);
+
+ gobject_class->finalize = GST_DEBUG_FUNCPTR (gst_mdns_device_finalize);
+
+ gst_device_class->create_element =
+ GST_DEBUG_FUNCPTR (gst_mdns_device_create_element);
+}
+
+/* Slightly unoptimized, ideally add gst_element_factory_from_uri */
+static GstElementFactory *
+get_factory_for_uri (GstURIType type, const gchar * uri)
+{
+ GError *err = NULL;
+ GstElementFactory *ret = NULL;
+ GstElement *elem = gst_element_make_from_uri (type, uri, NULL, &err);
+
+ if (!elem) {
+ GST_LOG ("Failed to make element from uri: %s", err->message);
+ g_clear_error (&err);
+ goto done;
+ }
+
+ ret = gst_element_get_factory (elem);
+
+ gst_object_unref (elem);
+
+done:
+ return ret;
+}
+
+static GstDevice *
+gst_mdns_device_new (GstElementFactory * factory, const gchar * name,
+ const gchar * uri)
+{
+ GstDevice *ret = NULL;
+ const GList *templates;
+ GstCaps *caps;
+
+ templates = gst_element_factory_get_static_pad_templates (factory);
+ caps = gst_static_pad_template_get_caps ((GstStaticPadTemplate *)
+ templates->data);
+
+ ret = GST_DEVICE (g_object_new (GST_TYPE_MDNS_DEVICE,
+ "display-name", name,
+ "device-class", gst_element_factory_get_metadata (factory, "klass"),
+ "caps", caps, NULL));
+
+ GST_MDNS_DEVICE (ret)->uri = g_strdup (uri);
+ GST_MDNS_DEVICE (ret)->uri_type = gst_element_factory_get_uri_type (factory);
+
+ gst_caps_unref (caps);
+
+ return ret;
+}
+
+static void
+remove_old_devices (ListenerContext * ctx)
+{
+ GstMDNSDeviceProvider *self = GST_MDNS_DEVICE_PROVIDER (ctx->provider);
+ GstClockTime now = g_get_monotonic_time ();
+ GSequenceIter *iter = g_sequence_get_begin_iter (ctx->last_seen_devices);
+
+ while (!g_sequence_iter_is_end (iter)) {
+ GstMDNSDevice *dev = GST_MDNS_DEVICE (g_sequence_get (iter));
+ GstClockTime age = now - dev->last_seen;
+
+ GST_LOG_OBJECT (self,
+ "Device %" GST_PTR_FORMAT " last seen %" GST_TIME_FORMAT " ago", dev,
+ GST_TIME_ARGS (age));
+
+ if (age > 4 * LISTEN_INTERVAL_SECONDS * G_USEC_PER_SEC) {
+ GSequenceIter *next = g_sequence_iter_next (iter);
+
+ GST_INFO_OBJECT (self, "Removing device %" GST_PTR_FORMAT, dev);
+
+ gst_device_provider_device_remove (ctx->provider, GST_DEVICE (dev));
+ g_hash_table_remove (ctx->devices, dev->uri);
+ g_sequence_remove (iter);
+ iter = next;
+ } else {
+ GST_LOG_OBJECT (self, "Keeping device %" GST_PTR_FORMAT, dev);
+ iter = g_sequence_get_end_iter (ctx->last_seen_devices);
+ }
+ }
+}
+
+static bool
+stop (void *p_cookie)
+{
+ bool ret;
+ ListenerContext *ctx = (ListenerContext *) p_cookie;
+
+ g_mutex_lock (&ctx->lock);
+ ret = ctx->stop;
+
+ if (!ctx->stop) {
+ remove_old_devices (ctx);
+ }
+
+ g_mutex_unlock (&ctx->lock);
+
+ return ret;
+}
+
+static void
+callback (void *p_cookie, gint status, const struct rr_entry *entry)
+{
+ ListenerContext *ctx = (ListenerContext *) p_cookie;
+ gchar err[128];
+ const struct rr_entry *tmp;
+ GHashTable *srvs = g_hash_table_new (g_str_hash, g_str_equal);
+ GstMDNSDeviceProvider *self = GST_MDNS_DEVICE_PROVIDER (ctx->provider);
+
+ g_mutex_lock (&ctx->lock);
+
+ if (ctx->stop)
+ goto done;
+
+ GST_DEBUG_OBJECT (self, "received new entries");
+
+ if (status < 0) {
+ mdns_strerror (status, err, sizeof (err));
+ GST_ERROR ("MDNS error: %s", err);
+ goto done;
+ }
+
+ for (tmp = entry; tmp; tmp = tmp->next) {
+ if (tmp->type == RR_SRV) {
+ g_hash_table_insert (srvs, (gpointer) tmp->name, (gpointer) tmp);
+ }
+ }
+
+ for (tmp = entry; tmp; tmp = tmp->next) {
+ if (tmp->type == RR_TXT) {
+ const struct rr_entry *srv;
+
+ srv = (const struct rr_entry *) g_hash_table_lookup (srvs, tmp->name);
+
+ if (!srv) {
+ GST_LOG_OBJECT (self, "No SRV associated with TXT entry for %s",
+ tmp->name);
+ continue;
+ }
+
+ if (g_str_has_suffix (tmp->name, "._rtsp._tcp.local")) {
+ gchar *path = NULL;
+ gchar *uri;
+ struct rr_data_txt *tmp_txt;
+ GstMDNSDevice *dev;
+
+ for (tmp_txt = tmp->data.TXT; tmp_txt; tmp_txt = tmp_txt->next) {
+ if (g_str_has_prefix (tmp_txt->txt, "path=")) {
+ path = tmp_txt->txt + 5;
+ }
+ }
+
+ if (path) {
+ uri =
+ g_strdup_printf ("rtsp://%s:%d/%s", srv->data.SRV.target,
+ srv->data.SRV.port, path);
+ } else {
+ uri =
+ g_strdup_printf ("rtsp://%s:%d", srv->data.SRV.target,
+ srv->data.SRV.port);
+ }
+
+ dev = GST_MDNS_DEVICE (g_hash_table_lookup (ctx->devices, uri));
+
+ GST_LOG_OBJECT (self, "Saw device at uri %s", uri);
+
+ if (dev) {
+ dev->last_seen = g_get_monotonic_time ();
+ GST_LOG_OBJECT (self,
+ "updating last_seen for device %" GST_PTR_FORMAT ": %"
+ G_GINT64_FORMAT, dev, dev->last_seen);
+ g_sequence_sort_changed_iter (dev->iter, cmp_last_seen_iter, NULL);
+ } else {
+ GstElementFactory *factory;
+ gchar *display_name;
+
+ if (!(factory = get_factory_for_uri (GST_URI_SRC, uri))) {
+ GST_LOG_OBJECT (self,
+ "Not registering device %s as no compatible factory was found",
+ tmp->name);
+ goto done;
+ }
+
+ display_name = g_strndup (tmp->name, strlen (tmp->name) - 17);
+ dev =
+ GST_MDNS_DEVICE (gst_mdns_device_new (factory, display_name,
+ uri));
+ g_free (display_name);
+ dev->last_seen = g_get_monotonic_time ();
+ GST_INFO_OBJECT (self,
+ "Saw new device %" GST_PTR_FORMAT " at %" G_GINT64_FORMAT
+ " with factory %" GST_PTR_FORMAT, dev, dev->last_seen, factory);
+ dev->iter =
+ g_sequence_insert_sorted (ctx->last_seen_devices, (gpointer) dev,
+ (GCompareDataFunc) cmp_last_seen, NULL);
+ g_hash_table_insert (ctx->devices, g_strdup (uri),
+ gst_object_ref (dev));
+ gst_device_provider_device_add (ctx->provider, GST_DEVICE (dev));
+ }
+
+ g_free (uri);
+ } else {
+ GST_LOG_OBJECT (self, "unknown protocol for %s", tmp->name);
+ continue;
+ }
+ }
+ }
+
+done:
+ g_hash_table_unref (srvs);
+ g_mutex_unlock (&ctx->lock);
+}
+
+static gpointer
+_listen (ListenerContext * ctx)
+{
+ gint r = 0;
+ gchar err[128];
+ struct mdns_ctx *mctx;
+ const gchar *ppsz_names[] = { "_rtsp._tcp.local" };
+ gint i_nb_names = 1;
+
+ if ((r = mdns_init (&mctx, MDNS_ADDR_IPV4, MDNS_PORT)) < 0)
+ goto err;
+
+ GST_INFO_OBJECT (ctx->provider, "Start listening");
+
+ if ((r = mdns_listen (mctx, ppsz_names, i_nb_names, RR_PTR,
+ LISTEN_INTERVAL_SECONDS, stop, callback, ctx)) < 0) {
+ mdns_destroy (mctx);
+ goto err;
+ }
+
+done:
+ GST_INFO_OBJECT (ctx->provider, "Done listening");
+
+ g_sequence_free (ctx->last_seen_devices);
+ g_hash_table_unref (ctx->devices);
+ g_mutex_clear (&ctx->lock);
+ g_free (ctx);
+
+ return NULL;
+
+err:
+ if (r < 0) {
+ mdns_strerror (r, err, sizeof (err));
+ GST_ERROR ("MDNS error: %s", err);
+ }
+
+ goto done;
+}
+
+static gboolean
+gst_mdns_device_provider_start (GstDeviceProvider * provider)
+{
+ GstMDNSDeviceProvider *self = GST_MDNS_DEVICE_PROVIDER (provider);
+ ListenerContext *ctx = g_new0 (ListenerContext, 1);
+
+ g_mutex_init (&ctx->lock);
+ ctx->provider = provider;
+ ctx->devices =
+ g_hash_table_new_full (g_str_hash, g_str_equal, g_free, g_object_unref);
+ ctx->last_seen_devices = g_sequence_new (NULL);
+ self->current_ctx = ctx;
+
+ g_thread_new (NULL, (GThreadFunc) _listen, ctx);
+
+ return TRUE;
+}
+
+static void
+gst_mdns_device_provider_stop (GstDeviceProvider * provider)
+{
+ GstMDNSDeviceProvider *self = GST_MDNS_DEVICE_PROVIDER (provider);
+
+ g_assert (self->current_ctx);
+
+ g_mutex_lock (&self->current_ctx->lock);
+ self->current_ctx->stop = true;
+ g_mutex_unlock (&self->current_ctx->lock);
+
+ self->current_ctx = NULL;
+}
+
+static void
+gst_mdns_device_provider_init (GstMDNSDeviceProvider * self)
+{
+}
+
+static void
+gst_mdns_device_provider_class_init (GstMDNSDeviceProviderClass * klass)
+{
+ GstDeviceProviderClass *dm_class = GST_DEVICE_PROVIDER_CLASS (klass);
+
+ dm_class->start = GST_DEBUG_FUNCPTR (gst_mdns_device_provider_start);
+ dm_class->stop = GST_DEBUG_FUNCPTR (gst_mdns_device_provider_stop);
+
+ gst_device_provider_class_set_static_metadata (dm_class,
+ "MDNS Device Provider", "Source/Network",
+ "List and provides MDNS-advertised source devices",
+ "Mathieu Duponchelle <mathieu@centricular.com>");
+}
projects / platform / upstream / gstreamer.git / commitdiff