httpd: add config option to limit number of clients

doc/mpdconf.example

@@ -252,6 +252,7 @@ input {
 ##	quality		"5.0"			# do not define if bitrate is defined
 #	bitrate		"128"			# do not define if quality is defined
 #	format		"44100:16:1"
+#	max_clients	"0"			# optional 0=no limit
 #}
 #
 # An example of a pulseaudio output (streaming to a remote pulseaudio server)

doc/user.xml

@@ -803,6 +803,16 @@ cd mpd-version</programlisting>
                   second.
                 </entry>
               </row>
+              <row>
+                <entry>
+                  <varname>max_clients</varname>
+                  <parameter>MC</parameter>
+                </entry>
+                <entry>
+                  Sets a limit, number of concurrent clients. When set
+                  to 0 no limit will apply.
+                </entry>
+              </row>
             </tbody>
           </tgroup>
         </informaltable>

src/output/httpd_internal.h

@@ -97,6 +97,12 @@ struct httpd_output {
 	 * function.
 	 */
 	char buffer[32768];
+
+	/**
+	 * The maximum and current number of clients connected 
+	 * at the same time.
+	 */
+	guint clients_max, clients_cnt;
 };
 
 /**

src/output/httpd_output_plugin.c

@@ -76,6 +76,8 @@ httpd_output_init(G_GNUC_UNUSED const struct audio_format *audio_format,
 	else
 		httpd->content_type = "application/octet-stream";
 
+	httpd->clients_max = config_get_block_unsigned(param,"max_clients", 0);
+
 	/* initialize listen address */
 
 	sin = (struct sockaddr_in *)&httpd->address;
@@ -124,6 +126,7 @@ httpd_client_add(struct httpd_output *httpd, int fd)
 				 httpd->encoder->plugin->tag == NULL);
 
 	httpd->clients = g_list_prepend(httpd->clients, client);
+	httpd->clients_cnt++;
 
 	/* pass metadata to client */
 	if (httpd->metadata)
@@ -146,10 +149,16 @@ httpd_listen_in_event(G_GNUC_UNUSED GIOChannel *source,
 	   connected */
 
 	fd = accept(httpd->fd, (struct sockaddr*)&sa, &sa_length);
-	if (fd >= 0)
-		httpd_client_add(httpd, fd);
-	else if (fd < 0 && errno != EINTR)
+	if (fd >= 0) {
+		/* can we allow additional client */
+		if (!httpd->clients_max ||
+		     httpd->clients_cnt < httpd->clients_max)
+			httpd_client_add(httpd, fd);
+		else
+			close(fd);
+	} else if (fd < 0 && errno != EINTR) {
 		g_warning("accept() failed: %s", g_strerror(errno));
+	}
 
 	g_mutex_unlock(httpd->mutex);
 
@@ -237,6 +246,7 @@ httpd_output_open(void *data, struct audio_format *audio_format,
 	/* initialize other attributes */
 
 	httpd->clients = NULL;
+	httpd->clients_cnt = 0;
 	httpd->timer = timer_new(audio_format);
 
 	g_mutex_unlock(httpd->mutex);
@@ -281,6 +291,7 @@ httpd_output_remove_client(struct httpd_output *httpd,
 	assert(client != NULL);
 
 	httpd->clients = g_list_remove(httpd->clients, client);
+	httpd->clients_cnt--;
 }
 
 void