X-Git-Url: https://git.sesse.net/?p=rdpsrv;a=blobdiff_plain;f=channels.c;fp=channels.c;h=6fc0cde9c82f47b35c66d342fc84144209ebb1bc;hp=0000000000000000000000000000000000000000;hb=b3ae47054997c61d01087d17a3ab001b0a54324b;hpb=1089fdeef6e23b3723f3e338cf52f1095d0ef682

diff --git a/channels.c b/channels.c
new file mode 100644
index 0000000..6fc0cde
--- /dev/null
+++ b/channels.c
@@ -0,0 +1,178 @@
+/* -*- c-basic-offset: 8 -*-
+   rdesktop: A Remote Desktop Protocol client.
+   Protocol services - Virtual channels
+   Copyright (C) Erik Forsberg <forsberg@cendio.se> 2003
+   Copyright (C) Matthew Chapman 2003
+
+   This program 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.
+
+   This program 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 this program; if not, write to the Free Software
+   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+*/
+
+#include "rdesktop.h"
+
+#define MAX_CHANNELS			4
+#define CHANNEL_CHUNK_LENGTH		1600
+#define CHANNEL_FLAG_FIRST		0x01
+#define CHANNEL_FLAG_LAST		0x02
+#define CHANNEL_FLAG_SHOW_PROTOCOL	0x10
+
+extern BOOL g_use_rdp5;
+extern BOOL g_encryption;
+
+VCHANNEL g_channels[MAX_CHANNELS];
+unsigned int g_num_channels;
+
+/* FIXME: We should use the information in TAG_SRV_CHANNELS to map RDP5
+   channels to MCS channels.
+
+   The format of TAG_SRV_CHANNELS seems to be
+
+   global_channel_no (uint16le)
+   number_of_other_channels (uint16le)
+   ..followed by uint16les for the other channels.
+*/
+
+VCHANNEL *
+channel_register(char *name, uint32 flags, void (*callback) (STREAM))
+{
+	VCHANNEL *channel;
+
+	if (g_num_channels >= MAX_CHANNELS)
+	{
+		error("Channel table full, increase MAX_CHANNELS\n");
+		return NULL;
+	}
+
+	channel = &g_channels[g_num_channels];
+	channel->mcs_id = MCS_GLOBAL_CHANNEL + 1 + g_num_channels;
+	strncpy(channel->name, name, 8);
+	channel->flags = flags;
+	channel->process = callback;
+	g_num_channels++;
+	return channel;
+}
+
+STREAM
+channel_init(VCHANNEL * channel, uint32 length)
+{
+	STREAM s;
+
+	s = sec_init(/*g_encryption ? SEC_ENCRYPT :*/ 0, length + 8);
+	s_push_layer(s, channel_hdr, 8);
+	return s;
+}
+
+void
+channel_send(STREAM s, VCHANNEL * channel)
+{
+	uint32 length, flags;
+	uint32 thislength, remaining;
+	uint8 *data;
+
+	/* first fragment sent in-place */
+	s_pop_layer(s, channel_hdr);
+	length = s->end - s->p - 8;
+
+	DEBUG_CLIPBOARD(("channel_send, length = %d\n", length));
+
+	thislength = MIN(length, CHANNEL_CHUNK_LENGTH);
+/* Note: In the original clipboard implementation, this number was
+   1592, not 1600. However, I don't remember the reason and 1600 seems
+   to work so.. This applies only to *this* length, not the length of
+   continuation or ending packets. */
+	remaining = length - thislength;
+	flags = (remaining == 0) ? CHANNEL_FLAG_FIRST | CHANNEL_FLAG_LAST : CHANNEL_FLAG_FIRST;
+	if (channel->flags & CHANNEL_OPTION_SHOW_PROTOCOL)
+		flags |= CHANNEL_FLAG_SHOW_PROTOCOL;
+
+	out_uint32_le(s, length);
+	out_uint32_le(s, flags);
+	data = s->end = s->p + thislength;
+	DEBUG_CLIPBOARD(("Sending %d bytes with FLAG_FIRST\n", thislength));
+	sec_send_to_channel(s, /*g_encryption ? SEC_ENCRYPT :*/ 0, channel->mcs_id);
+
+	/* subsequent segments copied (otherwise would have to generate headers backwards) */
+	while (remaining > 0)
+	{
+		thislength = MIN(remaining, CHANNEL_CHUNK_LENGTH);
+		remaining -= thislength;
+		flags = (remaining == 0) ? CHANNEL_FLAG_LAST : 0;
+		if (channel->flags & CHANNEL_OPTION_SHOW_PROTOCOL)
+			flags |= CHANNEL_FLAG_SHOW_PROTOCOL;
+
+		DEBUG_CLIPBOARD(("Sending %d bytes with flags %d\n", thislength, flags));
+
+		s = sec_init(/*g_encryption ? SEC_ENCRYPT : */0, thislength + 8);
+		out_uint32_le(s, length);
+		out_uint32_le(s, flags);
+		out_uint8p(s, data, thislength);
+		s_mark_end(s);
+		sec_send_to_channel(s, /*g_encryption ? SEC_ENCRYPT : */0, channel->mcs_id);
+
+		data += thislength;
+	}
+}
+
+void
+channel_process(STREAM s, uint16 mcs_channel)
+{
+	uint32 length, flags;
+	uint32 thislength;
+	VCHANNEL *channel = NULL;
+	unsigned int i;
+	STREAM in;
+
+	for (i = 0; i < g_num_channels; i++)
+	{
+		channel = &g_channels[i];
+		if (channel->mcs_id == mcs_channel)
+			break;
+	}
+
+	if (i >= g_num_channels)
+		return;
+
+	in_uint32_le(s, length);
+	in_uint32_le(s, flags);
+	if ((flags & CHANNEL_FLAG_FIRST) && (flags & CHANNEL_FLAG_LAST))
+	{
+		/* single fragment - pass straight up */
+		channel->process(s);
+	}
+	else
+	{
+		/* add fragment to defragmentation buffer */
+		in = &channel->in;
+		if (flags & CHANNEL_FLAG_FIRST)
+		{
+			if (length > in->size)
+			{
+				in->data = xrealloc(in->data, length);
+				in->size = length;
+			}
+			in->p = in->data;
+		}
+
+		thislength = MIN(s->end - s->p, in->data + in->size - in->p);
+		memcpy(in->p, s->p, thislength);
+		in->p += thislength;
+
+		if (flags & CHANNEL_FLAG_LAST)
+		{
+			in->end = in->p;
+			in->p = in->data;
+			channel->process(in);
+		}
+	}
+}