paulo@0: /*
paulo@0:  * $Id: rx_link.c,v 1.7 2004/02/01 08:17:12 hipnod Exp $
paulo@0:  *
paulo@0:  * Copyright (C) 2003 giFT project (gift.sourceforge.net)
paulo@0:  *
paulo@0:  * This program is free software; you can redistribute it and/or modify it
paulo@0:  * under the terms of the GNU General Public License as published by the
paulo@0:  * Free Software Foundation; either version 2, or (at your option) any
paulo@0:  * later version.
paulo@0:  *
paulo@0:  * This program is distributed in the hope that it will be useful, but
paulo@0:  * WITHOUT ANY WARRANTY; without even the implied warranty of
paulo@0:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
paulo@0:  * General Public License for more details.
paulo@0:  */
paulo@0: 
paulo@0: #include "gt_gnutella.h"
paulo@0: 
paulo@0: #include "rx_layer.h"
paulo@0: #include "rx_link.h"
paulo@0: 
paulo@0: /*****************************************************************************/
paulo@0: 
paulo@0: struct rx_link
paulo@0: {
paulo@0: 	/* TODO when the tx stack is implemented also
paulo@0: 	 * right now cleanup is too hard */
paulo@0: #if 0
paulo@0: 	struct io_source  *ios;
paulo@0: #endif
paulo@0: 	TCPC              *c;
paulo@0: 	input_id           id;
paulo@0: };
paulo@0: 
paulo@0: /*****************************************************************************/
paulo@0: 
paulo@0: /* Some macros for readability */
paulo@0: 
paulo@0: #define RX_LINK(rx) \
paulo@0: 	((struct rx_link *)((rx)->udata))
paulo@0: 
paulo@0: #define IO_SOURCE(rx_link) \
paulo@0: 	((rx_link)->ios)
paulo@0: 
paulo@0: /*****************************************************************************/
paulo@0: 
paulo@0: /* TODO: implement cached allocation */
paulo@0: #define RX_LINK_BUFSIZE      512
paulo@0: 
paulo@0: /*
paulo@0:  * This implementation is for bootstrapping the code onto
paulo@0:  * the present system.
paulo@0:  *
paulo@0:  * The low-level details of what we are actually reading
paulo@0:  * from should be abstracted away.
paulo@0:  */
paulo@0: static void read_data (int fd, input_id id, struct rx_layer *rx)
paulo@0: {
paulo@0: 	struct rx_link   *rx_link = RX_LINK(rx);
paulo@0: 	struct io_buf    *io_buf;
paulo@0: 	ssize_t           n;
paulo@0: 
paulo@0: 	/* we're processing data, we'd better be enabled */
paulo@0: 	assert (rx->enabled);
paulo@0: 
paulo@0: 	if (!(io_buf = io_buf_new (RX_LINK_BUFSIZE)))
paulo@0: 	{
paulo@0: 		gt_rx_stack_abort (rx->stack);
paulo@0: 		return;
paulo@0: 	}
paulo@0: 
paulo@0: 	if ((n = tcp_recv (rx_link->c, io_buf_write_ptr (io_buf), 
paulo@0: 	                   RX_LINK_BUFSIZE)) <= 0)
paulo@0: 	{
paulo@0: 		if (IO_DEBUG)
paulo@0: 		{
paulo@0: 			if (n < 0)
paulo@0: 				GT->DBGSOCK (GT, rx_link->c, "recv error: %s", GIFT_NETERROR());
paulo@0: 			else
paulo@0: 				GT->DBGSOCK (GT, rx_link->c, "recv error: socket closed");
paulo@0: 		}
paulo@0: 
paulo@0: 		io_buf_free (io_buf);
paulo@0: 		gt_rx_stack_abort (rx->stack);
paulo@0: 		return;
paulo@0: 	}
paulo@0: 
paulo@0: 	/* set the data as having been read */
paulo@0: 	io_buf_push (io_buf, n);
paulo@0: 
paulo@0: 	/*
paulo@0: 	 * Pass the data up the stack.
paulo@0: 	 */
paulo@0: 	gt_rx_layer_recv (rx, io_buf);
paulo@0: }
paulo@0: 
paulo@0: #if 0
paulo@0: /*
paulo@0:  * Receive data from the I/O source, and pass it up the stack
paulo@0:  */
paulo@0: static void recv_data (struct io_source *ios, struct io_buf *io_buf)
paulo@0: {
paulo@0: 	struct rx_layer   *rx;
paulo@0: 	struct rx_link    *rx_link;
paulo@0: 	ssize_t            n;
paulo@0: 
paulo@0:     rx      = ios->recv_data;
paulo@0: 	rx_link = RX_LINK(rx);
paulo@0: 
paulo@0: 	/*
paulo@0: 	 * Pass the data to an upper layer.
paulo@0: 	 */
paulo@0: 	gt_rx_layer_recv (rx, io_buf);
paulo@0: 
paulo@0: 	/*
paulo@0: 	 * ?? we have to free io_buf here ?? No.
paulo@0: 	 * gtk-gnutella passes off responsibility to the upper layers,
paulo@0: 	 * but why..
paulo@0: 	 */
paulo@0: #if 0
paulo@0: 	return n;
paulo@0: #endif
paulo@0: 	/*
paulo@0: 	 * Think i may understand why gtk-gnutella does it that way now:
paulo@0: 	 * in the partial packet case there may be unread data on the packet,
paulo@0: 	 * so we have to store that partial packet data in the intermediate
paulo@0: 	 * layers.
paulo@0: 	 *
paulo@0: 	 * I still wonder if its possible to use a static buffer at each layer
paulo@0: 	 * though...
paulo@0: 	 */
paulo@0: }
paulo@0: #endif
paulo@0: 
paulo@0: static void init_input (struct rx_layer *rx, struct rx_link *rx_link)
paulo@0: {
paulo@0: 	assert (rx_link->id == 0);
paulo@0: 	rx_link->id = input_add (rx_link->c->fd, rx, INPUT_READ,
paulo@0: 	                         (InputCallback)read_data, 0);
paulo@0: }
paulo@0: 
paulo@0: static void free_input (struct rx_layer *rx, struct rx_link *rx_link)
paulo@0: {
paulo@0: 	/*
paulo@0: 	 * This could be called multiple times on cleanup,
paulo@0: 	 * so we don't assert the id is 0 here.
paulo@0: 	 */
paulo@0: 	if (rx_link->id)
paulo@0: 	{
paulo@0: 		input_remove (rx_link->id);
paulo@0: 		rx_link->id = 0;
paulo@0: 	}
paulo@0: }
paulo@0: 
paulo@0: static void rx_link_enable (struct rx_layer *rx)
paulo@0: {
paulo@0: 	struct rx_link *rx_link = RX_LINK(rx);
paulo@0: 
paulo@0: #if 0
paulo@0: 	/* set the callback for getting data */
paulo@0: 	io_source_enable (IO_SOURCE(rx_link), IO_SOURCE_OP_RECV, recv_data, rx);
paulo@0: #endif
paulo@0: 
paulo@0: 	init_input (rx, rx_link);
paulo@0: }
paulo@0: 
paulo@0: static void rx_link_disable (struct rx_layer *rx)
paulo@0: {
paulo@0: 	struct rx_link *rx_link = RX_LINK(rx);
paulo@0: 
paulo@0: #if 0
paulo@0: 	io_source_disable (IO_SOURCE(rx_link), IO_SOURCE_OP_RECV);
paulo@0: #endif
paulo@0: 	free_input (rx, rx_link);
paulo@0: }
paulo@0: 
paulo@0: static BOOL rx_link_init (struct rx_layer *rx, void *udata)
paulo@0: {
paulo@0: 	struct rx_link *rx_link;
paulo@0: 	TCPC           *c = (TCPC *) udata;  /* ewwww */
paulo@0: 
paulo@0: 	if (!(rx_link = NEW (struct rx_link)))
paulo@0: 		return FALSE;
paulo@0: 
paulo@0: 	/* store the connection which we get from the upper layer...gross */
paulo@0: 	rx_link->c = c;
paulo@0: 
paulo@0: 	/* store our data in the rx structure */
paulo@0: 	rx->udata = rx_link;
paulo@0: 
paulo@0: 	return TRUE;
paulo@0: }
paulo@0: 
paulo@0: static void rx_link_destroy (struct rx_layer *rx)
paulo@0: {
paulo@0: 	struct rx_link *rx_link = RX_LINK(rx);
paulo@0: 
paulo@0: 	/*
paulo@0: 	 * rx_link_disable() should be called first
paulo@0: 	 */
paulo@0: 	assert (rx_link->id == 0);
paulo@0: 
paulo@0: 	/*
paulo@0: 	 * We would free the connection here, but its shared with
paulo@0: 	 * a GtNode that frees it also at the moment.
paulo@0: 	 */
paulo@0: #if 0
paulo@0: 	tcp_close (rx->c);
paulo@0: #endif
paulo@0: 
paulo@0: #if 0
paulo@0: 	io_source_free (rx_link->ios);
paulo@0: #endif
paulo@0: 
paulo@0: 	FREE (rx_link);
paulo@0: }
paulo@0: 
paulo@0: /*****************************************************************************/
paulo@0: 
paulo@0: struct rx_layer_ops gt_rx_link_ops =
paulo@0: {
paulo@0: 	rx_link_init,
paulo@0: 	rx_link_destroy,
paulo@0: 	rx_link_enable,
paulo@0: 	rx_link_disable,
paulo@0: 	NULL,           /* rx_link_recv */
paulo@0: };