trunk/rdesktop/channels.c

/* -*- 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 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 (!use_rdp5)
                return NULL;

        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;
        char *data;

        /* first fragment sent in-place */
        s_pop_layer(s, channel_hdr);
        length = s->end - s->p - 8;

        thislength = MIN(length, CHANNEL_CHUNK_LENGTH);
        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;
        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;

                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;
        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 = s->end - s->p;
                memcpy(in->p, s->p, thislength);
                s->p += thislength;
                s->end += thislength;

                if (flags & CHANNEL_FLAG_LAST)
                {
                        in->p = in->data;
                        channel->process(in);
                }
        }
}
1	forsberg	400	/* -- c-basic-offset: 8 --
2			rdesktop: A Remote Desktop Protocol client.
3	matthewc	432	Protocol services - Virtual channels
4	forsberg	400	Copyright (C) Erik Forsberg <forsberg@cendio.se> 2003
5	matthewc	432	Copyright (C) Matthew Chapman 2003
6	forsberg	400
7			This program is free software; you can redistribute it and/or modify
8			it under the terms of the GNU General Public License as published by
9			the Free Software Foundation; either version 2 of the License, or
10			(at your option) any later version.
11
12			This program is distributed in the hope that it will be useful,
13			but WITHOUT ANY WARRANTY; without even the implied warranty of
14			MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15			GNU General Public License for more details.
16
17			You should have received a copy of the GNU General Public License
18			along with this program; if not, write to the Free Software
19			Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
20			*/
21
22			#include "rdesktop.h"
23
24	matthewc	432	#define MAX_CHANNELS 4
25			#define CHANNEL_CHUNK_LENGTH 1600
26			#define CHANNEL_FLAG_FIRST 0x01
27			#define CHANNEL_FLAG_LAST 0x02
28			#define CHANNEL_FLAG_SHOW_PROTOCOL 0x10
29	forsberg	400
30	matthewc	432	extern BOOL use_rdp5;
31	jsorg71	437	extern BOOL g_encryption;
32	forsberg	400
33	matthewc	432	VCHANNEL g_channels[MAX_CHANNELS];
34			unsigned int g_num_channels;
35
36			/* FIXME: We should use the information in TAG_SRV_CHANNELS to map RDP5
37	forsberg	419	channels to MCS channels.
38
39	matthewc	432	The format of TAG_SRV_CHANNELS seems to be
40	forsberg	419
41			global_channel_no (uint16le)
42			number_of_other_channels (uint16le)
43			..followed by uint16les for the other channels.
44			*/
45
46	matthewc	432	VCHANNEL *
47			channel_register(char name, uint32 flags, void (callback) (STREAM))
48	forsberg	400	{
49	matthewc	432	VCHANNEL *channel;
50
51			if (!use_rdp5)
52			return NULL;
53
54			if (g_num_channels >= MAX_CHANNELS)
55	forsberg	400	{
56	matthewc	432	error("Channel table full, increase MAX_CHANNELS\n");
57			return NULL;
58	forsberg	400	}
59	matthewc	432
60			channel = &g_channels[g_num_channels];
61			channel->mcs_id = MCS_GLOBAL_CHANNEL + 1 + g_num_channels;
62			strncpy(channel->name, name, 8);
63			channel->flags = flags;
64			channel->process = callback;
65			g_num_channels++;
66			return channel;
67	forsberg	400	}
68
69	matthewc	432	STREAM
70	astrand	435	channel_init(VCHANNEL * channel, uint32 length)
71	forsberg	400	{
72	matthewc	432	STREAM s;
73
74	jsorg71	437	s = sec_init(g_encryption ? SEC_ENCRYPT : 0, length + 8);
75	matthewc	432	s_push_layer(s, channel_hdr, 8);
76			return s;
77			}
78
79			void
80	astrand	435	channel_send(STREAM s, VCHANNEL * channel)
81	matthewc	432	{
82			uint32 length, flags;
83			uint32 thislength, remaining;
84			char *data;
85
86			/* first fragment sent in-place */
87			s_pop_layer(s, channel_hdr);
88			length = s->end - s->p - 8;
89
90			thislength = MIN(length, CHANNEL_CHUNK_LENGTH);
91			remaining = length - thislength;
92	astrand	435	flags = (remaining == 0) ? CHANNEL_FLAG_FIRST \| CHANNEL_FLAG_LAST : CHANNEL_FLAG_FIRST;
93	matthewc	432	if (channel->flags & CHANNEL_OPTION_SHOW_PROTOCOL)
94			flags \|= CHANNEL_FLAG_SHOW_PROTOCOL;
95
96			out_uint32_le(s, length);
97			out_uint32_le(s, flags);
98			data = s->end = s->p + thislength;
99	jsorg71	437	sec_send_to_channel(s, g_encryption ? SEC_ENCRYPT : 0, channel->mcs_id);
100	matthewc	432
101			/* subsequent segments copied (otherwise would have to generate headers backwards) */
102			while (remaining > 0)
103	forsberg	400	{
104	matthewc	432	thislength = MIN(remaining, CHANNEL_CHUNK_LENGTH);
105			remaining -= thislength;
106			flags = (remaining == 0) ? CHANNEL_FLAG_LAST : 0;
107
108	jsorg71	437	s = sec_init(g_encryption ? SEC_ENCRYPT : 0, thislength + 8);
109	matthewc	432	out_uint32_le(s, length);
110			out_uint32_le(s, flags);
111			out_uint8p(s, data, thislength);
112			s_mark_end(s);
113	jsorg71	437	sec_send_to_channel(s, g_encryption ? SEC_ENCRYPT : 0, channel->mcs_id);
114	matthewc	432
115			data += thislength;
116	forsberg	400	}
117			}
118
119	matthewc	432	void
120			channel_process(STREAM s, uint16 mcs_channel)
121	forsberg	400	{
122	matthewc	432	uint32 length, flags;
123			uint32 thislength;
124			VCHANNEL *channel;
125			unsigned int i;
126			STREAM in;
127
128			for (i = 0; i < g_num_channels; i++)
129	forsberg	400	{
130	matthewc	432	channel = &g_channels[i];
131			if (channel->mcs_id == mcs_channel)
132			break;
133	forsberg	400	}
134	matthewc	432
135			if (i >= g_num_channels)
136			return;
137
138			in_uint32_le(s, length);
139			in_uint32_le(s, flags);
140			if ((flags & CHANNEL_FLAG_FIRST) && (flags & CHANNEL_FLAG_LAST))
141			{
142			/* single fragment - pass straight up */
143			channel->process(s);
144			}
145	forsberg	400	else
146			{
147	matthewc	432	/* add fragment to defragmentation buffer */
148			in = &channel->in;
149			if (flags & CHANNEL_FLAG_FIRST)
150			{
151			if (length > in->size)
152			{
153			in->data = xrealloc(in->data, length);
154			in->size = length;
155			}
156			in->p = in->data;
157			}
158	forsberg	400
159	matthewc	432	thislength = s->end - s->p;
160			memcpy(in->p, s->p, thislength);
161			s->p += thislength;
162			s->end += thislength;
163	forsberg	400
164	matthewc	432	if (flags & CHANNEL_FLAG_LAST)
165			{
166			in->p = in->data;
167			channel->process(in);
168			}
169			}
170	forsberg	400	}