kind of that

check

// 

if (TSHttpTxnClientReqGet(txnp, &req_bufp, &req_loc) != TS_SUCCESS) {
  TSError("couldn't retrieve client request header\n");
	return 0;
}

length_field_loc = TSMimeHdrFieldFind(req_bufp, req_loc, TS_MIME_FIELD_CONTENT_LENGTH, TS_MIME_LEN_CONTENT_LENGTH);
if (length_field_loc) {
	TSMimeHdrDestroy(req_bufp, length_field_loc);
	TSHandleMLocRelease(req_bufp, TS_NULL_MLOC, length_field_loc );
}