Added SocketCAN support to the hub application on the Raspberry Pi

applications/hub/targets/linux.rpi1/AvaHiMDNS.cxx

@@ -0,0 +1,140 @@
+/** \copyright
+ * Copyright (c) 2016, Stuart W. Baker
+ * All rights reserved
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are  permitted provided that the following conditions are met:
+ *
+ *  - Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *
+ *  - Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * \file AvaHiMDNS.cxx
+ *
+ * A simple abstraction to publish mDNS sevices using Avahi.
+ *
+ * @author Stuart Baker
+ * @date 30 July 2016
+ */
+
+#include <stdio.h>
+#include <pthread.h>
+#include <semaphore.h>
+#include <avahi-client/client.h>
+#include <avahi-client/publish.h>
+#include <avahi-common/simple-watch.h>
+#include <avahi-common/malloc.h>
+#include <avahi-common/error.h>
+
+#include "utils/macros.h"
+#include "openlcb/TcpDefs.hxx"
+
+static AvahiEntryGroup *group = nullptr;
+static AvahiSimplePoll *simplePoll = nullptr;
+static AvahiClient *client = nullptr;
+static sem_t wait;
+
+/** Avahi group callback.
+ */
+static void entry_group_callback(AvahiEntryGroup *g, AvahiEntryGroupState state,
+                                 void *userdata)
+{
+    group = g;
+}
+
+/** Avahi client callback.
+ */
+static void client_callback(AvahiClient *c, AvahiClientState state,
+                            void * userdata)
+{
+    switch (state)
+    {
+        default:
+            break;
+        case AVAHI_CLIENT_S_RUNNING:
+            printf("client running\n");
+            break;
+    }
+}
+
+/** mdns polling thread.
+ * @param unused unused parameter
+ * @return should never return
+ */
+static void *mdns_thread(void *unused)
+{
+    int error;
+
+    simplePoll = avahi_simple_poll_new();
+    HASSERT(simplePoll);
+
+    client = avahi_client_new(avahi_simple_poll_get(simplePoll),
+                              (AvahiClientFlags)0, client_callback, nullptr,
+                              &error);
+    printf("client created\n");
+    HASSERT(client);
+
+    sem_post(&wait);
+    avahi_simple_poll_loop(simplePoll);
+
+    return nullptr;
+}
+
+/** Start the mDNS client.
+ */
+void mdns_client_start()
+{
+    sem_init(&wait, 0, 0);
+
+    pthread_t thread;
+    pthread_create(&thread, nullptr, mdns_thread, nullptr);
+    printf("client start\n");
+
+    sem_wait(&wait);
+}
+
+/** Publish an mDNS name.
+ */
+void mdns_publish(const char *name, uint16_t port)
+{
+    name = avahi_strdup(name);
+
+    if (!group)
+    {
+        group = avahi_entry_group_new(client, entry_group_callback, nullptr);
+        if (!group) {
+            fprintf(stderr, "avahi_entry_group_new() failed: %s\n",
+                avahi_strerror(avahi_client_errno(client)));
+        }
+        HASSERT(group);
+    }
+
+    int result = avahi_entry_group_add_service(group, AVAHI_IF_UNSPEC,
+        AVAHI_PROTO_UNSPEC, (AvahiPublishFlags)0, name,
+        openlcb::TcpDefs::MDNS_SERVICE_NAME_GRIDCONNECT_CAN_TCP, NULL, NULL, port,
+        "platform=linux-x86-openmrn", NULL);
+
+    if (result != 0)
+    {
+        fprintf(stderr, "Error exporting mDNS name (%d) %s\n", result,
+            avahi_strerror(result));
+    }
+
+    HASSERT(result == 0);
+    avahi_entry_group_commit(group);
+}