channels.c File Reference

#include "rdesktop.h"

Include dependency graph for channels.c:

Go to the source code of this file.

Functions
VCHANNEL *	channel_register (RDPCLIENT *This, char *name, uint32 flags, void(*callback)(RDPCLIENT *, STREAM))
STREAM	channel_init (RDPCLIENT *This, VCHANNEL *channel, uint32 length)
void	channel_send (RDPCLIENT *This, STREAM s, VCHANNEL *channel)
void	channel_process (RDPCLIENT *This, STREAM s, uint16 mcs_channel)

Function Documentation

channel_init()

STREAM channel_init	(	RDPCLIENT *	This,
		VCHANNEL *	channel,
		uint32	length
	)

Definition at line 66 of file channels.c.

{
    STREAM s;
 
    s = sec_init(This, This->encryption ? SEC_ENCRYPT : 0, length + 8);
    s_push_layer(s, channel_hdr, 8);
    return s;
}

channel_process()

void channel_process	(	RDPCLIENT *	This,
		STREAM	s,
		uint16	mcs_channel
	)

Definition at line 127 of file channels.c.

{
    uint32 length, flags;
    uint32 thislength;
    VCHANNEL *channel = NULL;
    unsigned int i;
    STREAM in;
 
    for (i = 0; i < This->num_channels; i++)
    {
        channel = &This->channels[i];
        if (channel->mcs_id == mcs_channel)
            break;
    }
 
    if (i >= This->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(This, s);
    }
    else
    {
        /* add fragment to defragmentation buffer */
        in = &channel->in;
        if (flags & CHANNEL_FLAG_FIRST)
        {
            if (length > in->size)
            {
                in->data = (uint8 *) 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(This, in);
        }
    }
}

channel_register()

VCHANNEL * channel_register	(	RDPCLIENT *	This,
		char *	name,
		uint32	flags,
		void(*)(RDPCLIENT *, STREAM)	callback
	)

Definition at line 43 of file channels.c.

{
    VCHANNEL *channel;
 
    if (!This->use_rdp5)
        return NULL;
 
    if (This->num_channels >= MAX_CHANNELS)
    {
        error("Channel table full, increase MAX_CHANNELS\n");
        return NULL;
    }
 
    channel = &This->channels[This->num_channels];
    channel->mcs_id = MCS_GLOBAL_CHANNEL + 1 + This->num_channels;
    strncpy(channel->name, name, 8);
    channel->flags = flags;
    channel->process = callback;
    This->num_channels++;
    return channel;
}

channel_send()

void channel_send	(	RDPCLIENT *	This,
		STREAM	s,
		VCHANNEL *	channel
	)

Definition at line 76 of file channels.c.

{
    uint32 length, flags;
    uint32 thislength, remaining;
    uint8 *data;
 
    /* first fragment sent in-place */
    s_pop_layer(s, channel_hdr);
    length = s->end - s->p - sizeof(CHANNEL_PDU_HEADER);
 
    DEBUG_CHANNEL(("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_CHANNEL(("Sending %d bytes with FLAG_FIRST\n", thislength));
    sec_send_to_channel(This, s, This->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_CHANNEL(("Sending %d bytes with flags %d\n", thislength, flags));
 
        s = sec_init(This, This->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(This, s, This->encryption ? SEC_ENCRYPT : 0, channel->mcs_id);
 
        data += thislength;
    }
}