/* Copyright (C) 1998-99 Martin Baulig

   This file is part of LibGTop 1.0.

   Contributed by Martin Baulig <martin@home-of-linux.org>, April 1998.

   LibGTop is free software; you can redistribute it and/or modify it

   under the terms of the GNU General Public License as published by

   the Free Software Foundation; either version 2 of the License,

   or (at your option) any later version.

   LibGTop 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 General Public License

   for more details.

   You should have received a copy of the GNU General Public License

   along with LibGTop; see the file COPYING. If not, write to the

   Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,

   Boston, MA 02110-1301, USA.

*/

#include <config.h>

#include <glibtop.h>

#include <glibtop/open.h>

#include <glibtop/read.h>

#include <glibtop/error.h>

#include <glibtop/version.h>

#include <glibtop/sysdeps.h>

#include <glibtop/command.h>

#include <glibtop/gnuserv.h>

/* Opens pipe to gtop server. Returns 0 on success and -1 on error. */

void

glibtop_open_l (glibtop *server, const char *program_name,

		const unsigned long features, const unsigned flags)

{

	int connect_type;

	server->name = program_name;

	/* It is important to set _GLIBTOP_INIT_STATE_OPEN here when we

	 * do recursive calls to glibtop_init_r (). */

	server->flags |= _GLIBTOP_INIT_STATE_OPEN;

	server->error_method = GLIBTOP_ERROR_METHOD_DEFAULT;

	glibtop_debug ("SIZEOF: %zu - %zu - %zu - %zu - %zu - %zu",

		 sizeof (glibtop_command), sizeof (glibtop_response),

		 sizeof (glibtop_mountentry), sizeof (glibtop_union),

		 sizeof (glibtop_sysdeps), sizeof (glibtop_response_union));

	switch (server->method) {

	case GLIBTOP_METHOD_DIRECT:

		server->features = 0;

		break;

	case GLIBTOP_METHOD_INET:

		glibtop_debug ("Connecting to '%s' port %ld.",

			 server->server_host, server->server_port);

		connect_type = glibtop_make_connection

			(server->server_host, server->server_port,

			 &server->socket);

		glibtop_debug ("Connect Type is %d.", connect_type);

		server->flags |= _GLIBTOP_INIT_STATE_SERVER;

		server->features = -1;

		break;

	case GLIBTOP_METHOD_UNIX:

		glibtop_debug ("Connecting to Unix Domain Socket.");

		connect_type = glibtop_make_connection

			("unix", 0, &server->socket);

		glibtop_debug ("Connect Type is %d.", connect_type);

		server->flags |= _GLIBTOP_INIT_STATE_SERVER;

		server->features = -1;

		break;

	case GLIBTOP_METHOD_PIPE:

		glibtop_debug ("Opening pipe to server (%s).",

			 server->server_command);

		if (pipe (server->input) || pipe (server->output))

			glibtop_error_io_r (server, "cannot make a pipe");

		server->pid  = fork ();

		if (server->pid < 0) {

			glibtop_error_io_r (server, "fork failed");

		} else if (server->pid == 0) {

			close (0); close (1);

			close (server->input [0]); close (server->output [1]);

			dup2 (server->input [1], 1);

			dup2 (server->output [0], 0);

			execl (server->server_command, "libgtop-server", NULL);

			glibtop_error_io_r (server, "execl (%s)",

					    server->server_command);

			_exit (2);

		}

		close (server->input [1]);

		close (server->output [0]);

		server->flags |= _GLIBTOP_INIT_STATE_SERVER;

		server->features = -1;

		break;

	}

	/* If the server has been started, ask it for its features. */

	if (server->flags & _GLIBTOP_INIT_STATE_SERVER) {

		char version [BUFSIZ], buffer [BUFSIZ];

		glibtop_sysdeps sysdeps;

		size_t size, nbytes;

		/* First check whether the server version is correct. */

		sprintf (version, LIBGTOP_VERSION_STRING,

			 LIBGTOP_VERSION, LIBGTOP_SERVER_VERSION,

			 (guint) sizeof (glibtop_command),

			 (guint) sizeof (glibtop_response),

			 (guint) sizeof (glibtop_union),

			 (guint) sizeof (glibtop_sysdeps));

		size = strlen (version) + 1;

		glibtop_read_l (server, sizeof (nbytes), &nbytes);

		if (nbytes != size)

			glibtop_error_r (server,

					 "Requested %u bytes but got %u.",

					 (unsigned)size, (unsigned)nbytes);

		glibtop_read_l (server, nbytes, buffer);

		if (memcmp (version, buffer, size))

			glibtop_error_r (server, "server version is not %s",

					 LIBGTOP_VERSION);

		/* Now ask it for its features. */

		glibtop_call_l (server, GLIBTOP_CMND_SYSDEPS, 0, NULL,

				sizeof (glibtop_sysdeps), &sysdeps);

		server->features = sysdeps.features;

		memcpy (&server->sysdeps, &sysdeps, sizeof (glibtop_sysdeps));

		glibtop_debug ("Server features are %#0lx.",

			 server->features);

	}

	/* In any case, we call the open functions of our own sysdeps

	 * directory. */

	glibtop_debug ("Calling sysdeps open function.");

	glibtop_init_s (&server, features, flags);

}