paulo@0: /*
paulo@0:  * $Id: rx_inflate.c,v 1.10 2004/04/05 07:56:54 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_stack.h"
paulo@0: #include "rx_layer.h"
paulo@0: 
paulo@0: #include <zlib.h>
paulo@0: 
paulo@0: /*****************************************************************************/
paulo@0: 
paulo@0: /* this is small for testing purposes */
paulo@0: #define    RX_INFLATE_BUFSIZE   256
paulo@0: 
paulo@0: #define RX_INFLATE(rx) \
paulo@0: 	((struct rx_inflate *) (((rx)->udata)))
paulo@0: 
paulo@0: struct rx_inflate
paulo@0: {
paulo@0: 	z_stream       z;
paulo@0: 	BOOL           init_done;
paulo@0: };
paulo@0: 
paulo@0: /*****************************************************************************/
paulo@0: 
paulo@0: static BOOL rx_inflate_init (struct rx_layer *rx, void *udata)
paulo@0: {
paulo@0: 	struct rx_inflate *rx_inflate;
paulo@0: 
paulo@0: 	if (!(rx_inflate = NEW (struct rx_inflate)))
paulo@0: 		return FALSE;
paulo@0: 
paulo@0: 	/* inflateInit() may touch these variables */
paulo@0: 	rx_inflate->z.zalloc   = Z_NULL;
paulo@0: 	rx_inflate->z.zfree    = Z_NULL;
paulo@0: 	rx_inflate->z.opaque   = Z_NULL;
paulo@0: 	rx_inflate->z.next_in  = Z_NULL;
paulo@0: 	rx_inflate->z.avail_in = 0;
paulo@0: 
paulo@0: 	if (inflateInit (&rx_inflate->z) != Z_OK)
paulo@0: 	{
paulo@0: 		gt_rx_stack_abort (rx->stack);
paulo@0: 		return FALSE;
paulo@0: 	}
paulo@0: 
paulo@0: 	rx->udata = rx_inflate;
paulo@0: 
paulo@0: 	rx_inflate->init_done = TRUE;
paulo@0: 
paulo@0: 	return TRUE;
paulo@0: }
paulo@0: 
paulo@0: static void rx_inflate_destroy (struct rx_layer *rx)
paulo@0: {
paulo@0: 	struct rx_inflate *rx_inflate = RX_INFLATE(rx);
paulo@0: 
paulo@0: 	/*
paulo@0: 	 * We don't check the error here, there could very well be leftover data
paulo@0: 	 * and it would be annoying to print a message every time.
paulo@0: 	 */
paulo@0: 	inflateEnd (&rx_inflate->z);
paulo@0: 	rx_inflate->init_done = FALSE;
paulo@0: 
paulo@0: 	FREE (rx_inflate);
paulo@0: }
paulo@0: 
paulo@0: static void rx_inflate_enable (struct rx_layer *rx)
paulo@0: {
paulo@0: 	/* nothing -- we only process data when it comes towards us */
paulo@0: }
paulo@0: 
paulo@0: static void rx_inflate_disable (struct rx_layer *rx)
paulo@0: {
paulo@0: 	/* nothing */
paulo@0: }
paulo@0: 
paulo@0: /*
paulo@0:  * Handle the data from the lower layer, decompress it, and pass
paulo@0:  * it to the upper layer.
paulo@0:  */
paulo@0: static struct io_buf *read_buf (struct rx_layer *rx, struct io_buf *io_buf)
paulo@0: {
paulo@0: 	struct rx_inflate *rx_inflate   = RX_INFLATE(rx);
paulo@0: 	struct io_buf     *out_msg;
paulo@0: 	z_streamp          inz;
paulo@0: 	int                ret;
paulo@0: 	size_t             uncompressed_size;
paulo@0: 	size_t             compressed_read;
paulo@0: 	size_t             out_size     = RX_INFLATE_BUFSIZE;
paulo@0: 	size_t             avail;
paulo@0: 	static size_t      running_cnt  = 0;
paulo@0: 	static int         msg_count    = 0;
paulo@0: 
paulo@0: 	avail = io_buf_read_avail (io_buf);
paulo@0: 
paulo@0: 	if (avail == 0)
paulo@0: 		return NULL;
paulo@0: 
paulo@0: 	if (!(out_msg = io_buf_new (out_size)))
paulo@0: 	{
paulo@0: 		GT->dbg (GT, "couldn't allocate memory for recv buf");
paulo@0: 		gt_rx_stack_abort (rx->stack);
paulo@0: 		return NULL;
paulo@0: 	}
paulo@0: 
paulo@0: 	assert (rx_inflate->init_done);
paulo@0: 	inz = &rx_inflate->z;
paulo@0: 
paulo@0: 	inz->next_in   = io_buf_read_ptr (io_buf);
paulo@0: 	inz->avail_in  = avail;
paulo@0: 	inz->next_out  = io_buf_write_ptr (out_msg);
paulo@0: 	inz->avail_out = out_size;
paulo@0: 
paulo@0: 	ret = inflate (inz, Z_SYNC_FLUSH);
paulo@0: 
paulo@0: 	if (ret != Z_OK)
paulo@0: 	{
paulo@0: 		if (IO_DEBUG)
paulo@0: 			GT->dbg (GT, "zlib recv error: %d", ret);
paulo@0: 
paulo@0: 		gt_rx_stack_abort (rx->stack);
paulo@0: 		io_buf_free (out_msg);
paulo@0: 		return NULL;
paulo@0: 	}
paulo@0: 
paulo@0: 	uncompressed_size  = out_size - inz->avail_out;
paulo@0: 	compressed_read    = avail - inz->avail_in;
paulo@0: 
paulo@0: 	running_cnt += uncompressed_size;
paulo@0: 	if (IO_DEBUG && ++msg_count % 50 == 0)
paulo@0: 	{
paulo@0: 		GT->dbg (GT, "uncompressed %u bytes", running_cnt);
paulo@0: 		running_cnt = 0;
paulo@0: 	}
paulo@0: 
paulo@0: 	/* add the bytes we read to the new messge */
paulo@0: 	io_buf_push (out_msg, uncompressed_size);
paulo@0: 
paulo@0: 	/* pop the old bytes we read off the incoming message */
paulo@0: 	io_buf_pop (io_buf, compressed_read);
paulo@0: 
paulo@0: 	return out_msg;
paulo@0: }
paulo@0: 
paulo@0: /*
paulo@0:  * Parse the data into buffers, and send it to the upper layers.  packets to
paulo@0:  */
paulo@0: static void rx_inflate_recv (struct rx_layer *rx, struct io_buf *io_buf)
paulo@0: {
paulo@0: 	struct io_buf   *msg;
paulo@0: 
paulo@0: 	while (rx->enabled && (msg = read_buf (rx, io_buf)))
paulo@0: 	{
paulo@0: 		assert (msg != NULL);
paulo@0: 		gt_rx_layer_recv (rx, msg);
paulo@0: 
paulo@0: 		/* 
paulo@0: 		 * NOTE: gt_rx_layer_recv() may abort the stack here...  there's not much
paulo@0: 		 * we can do about that, but in practice that doesn't happen and we
paulo@0: 		 * won't access freed memory because the stack doesn't get freed until
paulo@0: 		 * the lowest rx layer is notified of the abort...pretty hacky.
paulo@0: 		 */
paulo@0: 	}
paulo@0: 
paulo@0: 	/* we have to free the buffer */
paulo@0: 	io_buf_free (io_buf);
paulo@0: }
paulo@0: 
paulo@0: /*****************************************************************************/
paulo@0: 
paulo@0: struct rx_layer_ops gt_rx_inflate_ops =
paulo@0: {
paulo@0: 	rx_inflate_init,
paulo@0: 	rx_inflate_destroy,
paulo@0: 	rx_inflate_enable,
paulo@0: 	rx_inflate_disable,
paulo@0: 	rx_inflate_recv,
paulo@0: };