Wireshark · Ethereal-dev: [Ethereal-dev] adding multiple values to tree

[Lars Dörner <mail@xxxxxxxxx>]

Hy

I got a PDU which is build like that: 

1. a value how many video rectangles are coming.
2. for each rectangle a header describing the rect followed by the
rect-data.

Now I'm dissecting this pdu. It works fine with Debug messages but 
trying to add it do the tree like this : 

- Protocol 
  	 -  number of rect
         	 - header rect 1
       	 - header rect 2
			...
 
Always brings this:   Warn Dissector bug, protocol XYZ, in packet 802:
proto.c:1895: failed assertion "DISSECTOR_ASSERT_NOT_REACHED"

 Following the code:


static int dissect_framebufferupdate(tvbuff_t * tvb, packet_info * pinfo,
proto_tree * tree)
{
	static uint16_t count = 0, i = 0;
	static unsigned int offset2 = 4;
	uint16_t n_rects = 0;
	uint32_t length = 0;	
	uint32_t offset = 0;
	uint32_t avaible = tvb_reported_length_remaining(tvb, offset);
	teststruct memstruct;
		
	if (avaible >= 4)
	{
		n_rects = tvb_get_ntohs(tvb,2);
		if (i == 0)
		{
			count = n_rects;
			i++;
		}
	}else
	{
		pinfo->desegment_offset = offset; 
		pinfo->desegment_len = 1;
		return (-1);
	}

	while(count>0)
	{

		if (avaible >(12+offset2))
		{
			memstruct.x = tvb_get_ntohs(tvb,(offset2));
			memstruct.y = tvb_get_ntohs(tvb,(2+offset2));
			memstruct.w = tvb_get_ntohs(tvb,(4+offset2));
			memstruct.h = tvb_get_ntohs(tvb,(6+offset2));
			memstruct.encoding = tvb_get_ntohl(tvb,(8+offset2));

		}else 
		{
			pinfo->desegment_offset = offset;
			pinfo->desegment_len =1;
			return (-1);
		}

		length = decoder(memstruct.x, memstruct.y, memstruct.w,
memstruct.h, memstruct.encoding);


		if (avaible <= (12 + length + offset2))
		{
			pinfo->desegment_offset = offset;
			pinfo->desegment_len = 1;
		
			return(-1);
		}else
		{
			proto_tree *ti,*xyz_tree;
/* Set the protocol column */
				
			if(check_col(pinfo->cinfo,COL_INFO))
			{
				col_add_str(pinfo->cinfo, COL_INFO,
"FrameBuffer Update");
			}

				if (tree) 
			{
				ti = proto_tree_add_item(tree,proto_xyz,
tvb, 0, -1, FALSE);
				xyz_tree = proto_item_add_subtree(ti,
ett_xyz);
				proto_tree_add_uint(xyz_tree,
hf_xyz_fb_update_n_rects, tvb, 2, 2, n_rects);
				proto_tree_add_int(xyz_tree,
hf_xyz_fb_update_x , tvb, 4, 2, memstruct.x);
				printf("x: %d\n",memstruct.x);
				proto_tree_add_int(xyz_tree,
hf_xyz_fb_update_y, tvb, 6, 2, memstruct.y);
				printf("y: %d\n",memstruct.y);
				proto_tree_add_int(xyz_tree,
hf_xyz_fb_update_w, tvb, 8, 2, memstruct.w);
				proto_tree_add_int(xyz_tree,
hf_xyz_fb_update_h, tvb, 10, 2, memstruct.h);
				proto_tree_add_int(xyz_tree,
hf_xyz_fb_update_encoding, tvb, 12, 4, memstruct.encoding);
			}
			count --;
			printf(" counter: %d\n", count);
			offset2 = (offset2 + 13 + length);
		}
	}

	if (count == 0 )
	{ 
		i = 0;
		offset2 = 0x04;
	}
	

}