add: relay/piface support

handlers/discovery.c

@@ -0,0 +1,72 @@
+#include <string.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <uuid/uuid.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <arpa/inet.h>
+#include <unistd.h>
+#include <netdb.h>
+#include <errno.h>
+
+#include <logger.h>
+#include <handlers.h>
+#include <helpers.h>
+#include <binn.h>
+#include <enums.h>
+
+void
+handler_discovery(int fd, controller_t *controller)
+{
+    ssize_t bytes_transferred;
+    uint16_t discovery_answer_port;
+    struct sockaddr_in si_other;
+    socklen_t slen = sizeof(si_other);
+
+    if((bytes_transferred = recvfrom(fd, &discovery_answer_port, sizeof(discovery_answer_port), 0, (struct sockaddr *) &si_other, &slen)) <= 0)
+    {
+        LOG_ERROR("received invalid discovery from %s", inet_ntoa(si_other.sin_addr));
+        return;
+    }
+    LOG_DEBUG("received discovery from %s for port %d", inet_ntoa(si_other.sin_addr), discovery_answer_port);
+
+    if(discovery_answer_port == 0)
+    {
+        LOG_ERROR("invalid port received");
+        return;
+    }
+
+    binn *map = binn_map();
+
+    binn_map_set_blob(map, DISCOVERY_MAPPING_ID, &controller->id, sizeof(uuid_t));
+    binn_map_set_str(map, DISCOVERY_MAPPING_NAME, controller->name);
+    binn_map_set_uint32(map, DISCOVERY_MAPPING_COMMAND_PORT, controller->command_port);
+    binn_map_set_uint8(map, DISCOVERY_MAPPING_RELAY_COUNT, controller->relay_count);
+
+    void *payload = binn_ptr(map);
+    size_t payload_size = binn_size(map);
+
+    int fd_answer = helper_connect_tcp_server(inet_ntoa(si_other.sin_addr), discovery_answer_port);
+    if(fd_answer == -1)
+    {
+        LOG_ERROR("error during connecting");
+        binn_free(map);
+        return;
+    }
+
+    if((bytes_transferred = send(fd_answer, &payload_size, sizeof(payload_size), 0)) <= 0)
+    {
+        LOG_ERROR("error during sending");
+        binn_free(map);
+        return;
+    }
+    if((bytes_transferred = send(fd_answer, payload, payload_size, 0)) <= 0)
+    {
+        LOG_ERROR("error during sending");
+        binn_free(map);
+        return;
+    }
+
+    close(fd_answer);
+}