From 4a9df9b604cec6ee4b4a6f01ef940443583f7573 Mon Sep 17 00:00:00 2001
From: Nathanael Sensfelder <SpamShield0@MultiAgentSystems.org>
Date: Thu, 26 Dec 2019 18:32:26 +0100
Subject: Still working on the daemonization (and rewrite).

I am not sure that what I am doing is going to provide what was
requested in https://github.com/nsensfel/relabsd/issues/3 but it will at
the very least turn relabsd into a proper daemon, and the additions will
help create some kind of relabsd device manager if someone needs such a
thing.
---
 src/server/communication_node.c | 177 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 177 insertions(+)
 create mode 100644 src/server/communication_node.c

(limited to 'src/server/communication_node.c')

diff --git a/src/server/communication_node.c b/src/server/communication_node.c
new file mode 100644
index 0000000..70c7323
--- /dev/null
+++ b/src/server/communication_node.c
@@ -0,0 +1,177 @@
+/**** POSIX *******************************************************************/
+#include <sys/socket.h>
+#include <sys/un.h>
+
+#include <errno.h>
+#include <fcntl.h>
+#include <string.h>
+#include <unistd.h>
+
+/**** RELABSD *****************************************************************/
+#include <relabsd/debug.h>
+
+/******************************************************************************/
+/**** LOCAL FUNCTIONS *********************************************************/
+/******************************************************************************/
+
+static int create_socket (int result [const restrict static 1])
+{
+   errno = 0;
+
+   *result = socket(AF_UNIX, SOCK_STREAM, 0);
+
+   if (*result == -1)
+   {
+      RELABSD_FATAL
+      (
+         "Unable to create server socket: %s.",
+         strerror(errno)
+      );
+
+      return -1;
+   }
+
+   return 0;
+}
+
+static int bind_socket
+(
+   const char socket_name [const restrict static 1],
+   const int socket
+)
+{
+   struct sockaddr_un addr;
+
+
+   memset(&addr, 0, sizeof(struct sockaddr_un));
+
+   addr.sun_family = AF_UNIX;
+
+   strncpy
+   (
+      (void *) addr.sun_path,
+      (const void *) socket_name,
+      (sizeof(addr.sun_path) - 1)
+   );
+
+   errno = 0;
+
+   if
+   (
+      bind
+      (
+         socket,
+         (const struct sockaddr *) &addr,
+         (socklen_t) sizeof(struct sockaddr_un)
+      )
+      == -1
+   )
+   {
+      RELABSD_FATAL
+      (
+         "Unable to bind communication socket to %s: %s.",
+         socket_name,
+         strerror(errno)
+      );
+
+      return -1;
+   }
+
+   return 0;
+}
+
+static int set_socket_to_unblocking (const int socket)
+{
+   int current_flags;
+
+   errno = 0;
+   current_flags = fcntl(socket, F_GETFD);
+
+   if (current_flags == -1)
+   {
+      RELABSD_FATAL
+      (
+         "Unable to get communication socket properties: %s.",
+         strerror(errno)
+      );
+
+      return -1;
+   }
+
+   errno = 0;
+   current_flags = fcntl(socket, F_SETFD, (current_flags | O_NONBLOCK));
+
+   if (current_flags == -1)
+   {
+      RELABSD_FATAL
+      (
+         "Unable to set communication socket properties: %s.",
+         strerror(errno)
+      );
+
+      return -2;
+   }
+
+   return 0;
+}
+
+static int set_socket_as_listener (const int socket)
+{
+   errno = 0;
+
+   if (listen(socket, 0) == -1)
+   {
+      RELABSD_FATAL
+      (
+         "Unable to set server socket properties: %s.",
+         strerror(errno)
+      );
+
+      return -1;
+   }
+
+   return 0;
+}
+
+/******************************************************************************/
+/**** EXPORTED FUNCTIONS ******************************************************/
+/******************************************************************************/
+int relabsd_server_create_communication_node
+(
+   const char socket_name [const restrict static 1],
+   int socket [const restrict static 1]
+)
+{
+   if (create_socket(socket) < 0)
+   {
+      return -1;
+   }
+
+   if (bind_socket(socket_name, *socket) < 0)
+   {
+      /* TODO: err message. */
+      (void) close(*socket);
+
+      return -1;
+   }
+
+   /*
+   if (set_socket_to_unblocking(*socket) < 0)
+   {
+      /* TODO: err message. *//*
+      (void) close(*socket);
+
+      return -1;
+   }
+   */
+
+   if (set_socket_as_listener(*socket) < 0)
+   {
+      /* TODO: err message. */
+      (void) close(*socket);
+
+      return -1;
+   }
+
+   return 0;
+}
-- 
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