static int
dissect_beep_tree(tvbuff_t *tvb, int offset, packet_info *pinfo,
proto_tree *tree, struct beep_request_val *request_val,
struct beep_proto_data *beep_frame_data)
{
proto_tree *ti = NULL, *hdr = NULL;
/*proto_item *hidden_item;*/
int st_offset, msgno, ansno, seqno, size, channel, ackno, window, cc,
more;
const char * cmd_temp = NULL;
int is_ANS = 0;
st_offset = offset;
if (tvb_strneql(tvb, offset, "MSG ", 4) == 0)
cmd_temp = "Command: MSG";
if (tvb_strneql(tvb, offset, "RPY ", 4) == 0)
cmd_temp = "Command: RPY";
if (tvb_strneql(tvb, offset, "ERR ", 4) == 0)
cmd_temp = "Command: ERR";
if (tvb_strneql(tvb, offset, "NUL ", 4) == 0)
cmd_temp = "Command: NUL";
if (tvb_strneql(tvb, offset, "ANS ", 4) == 0) {
cmd_temp = "Command: ANS";
is_ANS = 1;
}
if (cmd_temp != NULL) {
if (tree) {
hdr = proto_tree_add_subtree(tree, tvb, offset, header_len(tvb, offset) + 2,
ett_header, NULL, "Header");
ti = proto_tree_add_item(hdr, hf_beep_cmd, tvb, offset, 3, ENC_NA|ENC_ASCII);
/* Include space */
proto_item_set_len(ti, 4);
proto_tree_add_boolean(hdr, hf_beep_req, tvb, offset, 3, TRUE);
}
offset += 4;
/* Get the channel */
offset += dissect_beep_int(tvb, offset, hdr, hf_beep_channel, &channel, req_chan_hfa);
offset += 1; /* Skip the space */
/* Dissect the message number */
offset += dissect_beep_int(tvb, offset, hdr, hf_beep_msgno, &msgno, req_msgno_hfa);
offset += 1; /* skip the space */
/* Insert the more elements ... */
if ((more = dissect_beep_more(tvb, pinfo, offset, hdr)) >= 0) {
/* Figure out which direction this is in and what mime_hdr flag to
* add to the beep_frame_data. If there are missing segments, this code
* will get it wrong!
*/
set_mime_hdr_flags(more, request_val, beep_frame_data, pinfo);
}
else { /* Protocol violation, so dissect rest as undisectable */
if (tree && (tvb_length_remaining(tvb, offset) > 0)) {
proto_tree_add_item(tree, hf_beep_payload_undissected, tvb, offset,
tvb_length_remaining(tvb, offset), ENC_NA|ENC_ASCII);
}
return -1;
}
offset += 2; /* Skip the flag and the space ... */
/* now for the seqno */
offset += dissect_beep_int(tvb, offset, hdr, hf_beep_seqno, &seqno, req_seqno_hfa);
offset += 1; /* skip the space */
offset += dissect_beep_int(tvb, offset, hdr, hf_beep_size, &size, req_size_hfa);
if (request_val) /* FIXME, is this the right order ... */
request_val -> size = size; /* Stash this away */
else if (beep_frame_data) {
beep_frame_data->pl_size = size;
if (beep_frame_data->pl_size < 0) beep_frame_data->pl_size = 0; /* FIXME: OK? */
}
/* offset += 1; skip the space */
if (is_ANS) { /* We need to put in the ansno */
offset += 1; /* skip the space */
/* Dissect the message number */
offset += dissect_beep_int(tvb, offset, hdr, hf_beep_ansno, &ansno, req_ansno_hfa);
}
if ((cc = check_term(tvb, pinfo, offset, hdr)) <= 0) {
/* We dissect the rest as data and bail ... */
if (tree && (tvb_length_remaining(tvb, offset) > 0)) {
proto_tree_add_item(tree, hf_beep_payload_undissected, tvb, offset,
tvb_length_remaining(tvb, offset), ENC_NA|ENC_ASCII);
}
return -1;
}
offset += cc;
/* Insert MIME header ... */
if (beep_frame_data && beep_frame_data->mime_hdr)
offset += dissect_beep_mime_header(tvb, pinfo, offset, beep_frame_data, hdr);
/* Now for the payload, if any */
if (tvb_length_remaining(tvb, offset) > 0) { /* Dissect what is left as payload */
int pl_size = MIN(size, tvb_length_remaining(tvb, offset));
/* Except, check the payload length, and only dissect that much */
/* We need to keep track, in the conversation, of how much is left
* so in the next packet, we can figure out what is part of the payload
* and what is the next message
*/
if (tree) {
proto_tree_add_item(tree, hf_beep_payload, tvb, offset, pl_size, ENC_NA|ENC_ASCII);
}
offset += pl_size;
if (request_val) {
request_val->size -= pl_size;
if (request_val->size < 0) request_val->size = 0;
}
else if (beep_frame_data) {
beep_frame_data->pl_size -= pl_size;
if (beep_frame_data->pl_size < 0) beep_frame_data->pl_size = 0;
}
}
/* If anything else left, dissect it ... */
if (tvb_length_remaining(tvb, offset) > 0)
offset += dissect_beep_tree(tvb, offset, pinfo, tree, request_val, beep_frame_data);
} else if (tvb_strneql(tvb, offset, "SEQ ", 4) == 0) {
if (tree) {
ti = proto_tree_add_item(hdr, hf_beep_cmd, tvb, offset, 3, ENC_NA|ENC_ASCII);
/* Include space */
proto_item_set_len(ti, 4);
}
offset += 3;
/* Now check the space: FIXME */
offset += 1;
offset += dissect_beep_int(tvb, offset, tree, hf_beep_channel, &channel, seq_chan_hfa);
/* Check the space: FIXME */
offset += 1;
offset += dissect_beep_int(tvb, offset, tree, hf_beep_ackno, &ackno, seq_ackno_hfa);
/* Check the space: FIXME */
offset += 1;
offset += dissect_beep_int(tvb, offset, tree, hf_beep_window, &window, seq_window_hfa);
if ((cc = check_term(tvb, pinfo, offset, tree)) <= 0) {
/* We dissect the rest as data and bail ... */
if (tree && (tvb_length_remaining(tvb, offset) > 0)) {
proto_tree_add_item(tree, hf_beep_payload_undissected, tvb, offset,
tvb_length_remaining(tvb, offset), ENC_NA|ENC_ASCII);
}
return -1;
}
offset += cc;
} else if (tvb_strneql(tvb, offset, "END", 3) == 0) {
proto_tree *tr = NULL;
if (tree) {
tr = proto_tree_add_subtree(tree, tvb, offset, MIN(5, MAX(0, tvb_length_remaining(tvb, offset))),
ett_trailer, NULL, "Trailer");
proto_tree_add_item(hdr, hf_beep_cmd, tvb, offset, 3, ENC_NA|ENC_ASCII);
}
offset += 3;
if ((cc = check_term(tvb, pinfo, offset, tr)) <= 0) {
/* We dissect the rest as data and bail ... */
if (tree && (tvb_length_remaining(tvb, offset) > 0)) {
proto_tree_add_item(tree, hf_beep_payload_undissected, tvb, offset,
tvb_length_remaining(tvb, offset), ENC_NA|ENC_ASCII);
}
return -1;
}
offset += cc;
}
if (tvb_length_remaining(tvb, offset) > 0) { /* Dissect anything left over */
int pl_size = 0;
if (request_val) {
pl_size = MIN(request_val->size, tvb_length_remaining(tvb, offset));
if (pl_size == 0) { /* The whole of the rest must be payload */
pl_size = tvb_length_remaining(tvb, offset); /* Right place ? */
}
} else if (beep_frame_data) {
pl_size = MIN(beep_frame_data->pl_size, tvb_length_remaining(tvb, offset));
} else { /* Just in case */
pl_size = tvb_length_remaining(tvb, offset);
}
/* Take care here to handle the payload correctly, and if there is
* another message here, then handle it correctly as well.
*/
/* If the pl_size == 0 and the offset == 0?, then we have not processed
* anything in this frame above, so we better treat all this data as
* payload to avoid recursion loops
*/
if (pl_size == 0 && offset == st_offset)
pl_size = tvb_length_remaining(tvb, offset);
if (pl_size > 0) {
if (tree) {
proto_tree_add_item(tree, hf_beep_payload, tvb, offset, pl_size, ENC_NA|ENC_ASCII);
}
offset += pl_size; /* Advance past the payload */
if (request_val){
request_val->size -= pl_size; /* Reduce payload by what we added */
if (request_val->size < 0) request_val->size = 0;
}
else if (beep_frame_data) {
beep_frame_data->pl_size -= pl_size;
if (beep_frame_data->pl_size < 0) beep_frame_data->pl_size = 0;
}
}
if (tvb_length_remaining(tvb, offset) > 0) {
offset += dissect_beep_tree(tvb, offset, pinfo, tree, request_val, beep_frame_data);
}
}
return offset - st_offset;
}
static void
dissect_beep(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
{
int offset;
struct beep_proto_data *beep_frame_data = NULL;
proto_tree *beep_tree = NULL, *ti = NULL;
conversation_t *conversation = NULL;
struct beep_request_key request_key, *new_request_key;
struct beep_request_val *request_val = NULL;
offset = 0;
/* If we have per frame data, use that, else, we must have lost the per-
* frame data, and we have to do a full dissect pass again.
*
* The per-frame data tells us how much of this frame is left over from a
* previous frame, so we dissect it as payload and then try to dissect the
* rest.
*
* We use the conversation to build up info on the first pass over the
* packets of type BEEP, and record anything that is needed if the user
* does random dissects of packets in per packet data.
*
* Once we have per-packet data, we don't need the conversation stuff
* anymore, but if per-packet data and conversation stuff gets deleted, as
* it does under some circumstances when a rescan is done, it all gets
* rebuilt.
*/
/* Find out what conversation this packet is part of ... but only
* if we have no information on this packet, so find the per-frame
* info first.
*/
beep_frame_data = p_get_proto_data(pinfo->fd, proto_beep);
if (!beep_frame_data) {
conversation = find_conversation(pinfo->fd->num, &pinfo->src, &pinfo->dst, pinfo->ptype,
pinfo->srcport, pinfo->destport, 0);
if (conversation == NULL) { /* No conversation, create one */
conversation = conversation_new(pinfo->fd->num, &pinfo->src, &pinfo->dst, pinfo->ptype,
pinfo->srcport, pinfo->destport, 0);
}
/*
* Check for and insert an entry in the request table if does not exist
*/
request_key.conversation = conversation->index;
request_val = (struct beep_request_val *)g_hash_table_lookup(beep_request_hash, &request_key);
if (!request_val) { /* Create one */
new_request_key = se_alloc(sizeof(struct beep_request_key));
new_request_key->conversation = conversation->index;
request_val = se_alloc(sizeof(struct beep_request_val));
request_val->processed = 0;
request_val->size = 0;
g_hash_table_insert(beep_request_hash, new_request_key, request_val);
}
}
col_set_str(pinfo->cinfo, COL_PROTOCOL, "BEEP");
if (check_col(pinfo->cinfo, COL_INFO)) { /* Check the type ... */
/* "tvb_format_text()" is passed a value that won't go past the end
* of the packet, so it won't throw an exception. */
col_add_str(pinfo->cinfo, COL_INFO, tvb_format_text(tvb, offset, tvb_length_remaining(tvb, offset)));
}
/* Here, we parse the message so we can retrieve the info we need, which
* is that there is some payload left from a previous segment on the
* front of this segment ... This all depends on TCP segments not getting
* out of order ...
*
* As a huge kludge, we push the checking for the tree down into the code
* and process as if we were given a tree but not call the routines that
* adorn the protocol tree if they were NULL.
*/
if (tree) { /* Build the tree info ... */
ti = proto_tree_add_item(tree, proto_beep, tvb, offset, -1, FALSE);
beep_tree = proto_item_add_subtree(ti, ett_beep);
}
/* Check the per-frame data and the conversation for any left-over
* payload from the previous frame
*
* We check that per-frame data exists first, and if so, use it,
* else we use the conversation data.
*
* We create per-frame data here as well, but we must ensure we create it
* after we have done the check for per-frame or conversation data.
*
* We also depend on the first frame in a group having a pl_size of 0.
*/
if (beep_frame_data && beep_frame_data->pl_left > 0) {
int pl_left = beep_frame_data->pl_left;
pl_left = MIN(pl_left, tvb_length_remaining(tvb, offset));
/* Add the payload bit, only if we have a tree */
if (tree) {
proto_tree_add_text(beep_tree, tvb, offset, pl_left, "Payload: %s",
tvb_format_text(tvb, offset, pl_left));
}
offset += pl_left;
}
else if (request_val && request_val->size > 0) {
int pl_left = request_val->size;
request_val->size = 0;
/* We create the frame data here for this case, and
* elsewhere for other frames
*/
beep_frame_data = se_alloc(sizeof(struct beep_proto_data));
beep_frame_data->pl_left = pl_left;
beep_frame_data->pl_size = 0;
beep_frame_data->mime_hdr = 0;
p_add_proto_data(pinfo->fd, proto_beep, beep_frame_data);
}
/* Set up the per-frame data here if not already done so
* This _must_ come after the checks above ...
*/
if (beep_frame_data == NULL) {
beep_frame_data = se_alloc(sizeof(struct beep_proto_data));
beep_frame_data->pl_left = 0;
beep_frame_data->pl_size = 0;
beep_frame_data->mime_hdr = 0;
p_add_proto_data(pinfo->fd, proto_beep, beep_frame_data);
}
if (tvb_length_remaining(tvb, offset) > 0) {
offset += dissect_beep_tree(tvb, offset, pinfo, beep_tree, request_val, beep_frame_data);
}
}
