["Oren Mazor" <oren.mazor@xxxxxxxxx>]

I eventually went back and fixed it up with your suggestions.

Thanks to all for the advice and help :)

Cheers,
Oren

static tvbuff_t *
filterPadding(tvbuff_t *tvb,packet_info *pinfo)
{
	const guint8 *orig_buffer = tvb_get_ptr(tvb, 0, -1);
	int orig_buffer_len = tvb_length(tvb);
	guint8 *new_buffer = g_malloc(orig_buffer_len);
	int new_buffer_len = orig_buffer_len;

	int i,j; //i is our READ pointer, and j is the WRITE pointer
	for(i=0,j=0;i<orig_buffer_len;i++,j++)
	{	
		new_buffer[j] = orig_buffer[i];
		if(orig_buffer[i] == 126)//0x7E = 126
		{
			if(orig_buffer[i+1] == 85)//0x85 = 55
			{
				new_buffer_len--;
				i++;
			}
		}
		
	}
	//create the new tvb
    tvbuff_t *next_tvb =  
tvb_new_real_data(new_buffer,new_buffer_len,new_buffer_len);
    tvb_set_child_real_data_tvbuff(tvb, next_tvb);
    add_new_data_source(pinfo, next_tvb, "Check");
	tvb_set_free_cb(next_tvb, g_free);
	return next_tvb;
}


On Wed, 11 May 2005 01:51:12 -0400, Guy Harris <gharris@xxxxxxxxx> wrote:

> Oren Mazor wrote:
>
> > static tvbuff_t *
> > cleanUpEscapeSequence(tvbuff_t *tvb, packet_info *pinfo)
> > {
> >     //the original bytes
> >     char* orig_buffer = tvb_memdup(tvb, 0, tvb_length(tvb));
>
> There's no need to copy the original bytes;
>
> 	char *orig_buffer = tvb_get_ptr(tvb, 0, -1);
>
> should suffice.
>
> >     //the size of above buffer
> >     int buffer_size = strlen(orig_buffer);
>
> As noted, that's the wrong way to get the size of the buffer; you should  
> use tvb_length(tvb) instead.
>
> >     //the size of our new buffer (initially the same as original buffer)
> >     int new_buffer_size = buffer_size;
> >     //buffer to hold the resulting bytes
> >     char* new_buffer[buffer_size];
>
> That will be allocated on the stack, and will not be valid after  
> "cleanUpEscapeSequence()" returns.  Instead, do
>
> 	char *new_buffer = g_malloc(buffer_size);
>
> ("g_malloc()" aborts if the allocation fails; you could also use  
> "malloc()", but your dissector will need to check for a null pointer  
> being returned, and quit.)
>
> >     if(new_buffer_size != buffer_size)
> >     {//we've had a change, if the two buffer size dont match
> >         //create the new tvb
> >         tvbuff_t *next_tvb = tvb_new_real_data(*new_buffer,  
> > new_buffer_size,  new_buffer_size);
> >         tvb_set_child_real_data_tvbuff(tvb, next_tvb);
> >          add_new_data_source(pinfo, next_tvb, "Check");
>
> In this case, there's one more thing to do:
>
> 		tvb_set_free_cb(next_tvb, g_free);
>
> to arrange that when "next_tvb" is freed, the data for it is freed.  
> (This allows different routines to be used to free the tvbuff.)
>
> >         return next_tvb;
> >     }
> >     else
> >         return tvb;
>
> And here you'd free "new_buffer", as you aren't creating a new tvbuff.
>
>
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