identifying last request on a tcp connection. (no replies)

I've been trying to identify the last HTTP request from a buffer of 10 requests sent on a TCP connection in nginx. I've tried to use the header_in field in the ngx_http_request_t by checking if the pos field for the header_in is equal to the last field. This condition holds true twice, once on the first request and then on the last request. My program intends to break out once the last request is identified and hence, has been breaking after encountering the first request because of this check.

Can someone help me identify the problem with my approach and point to the right solution? Thanks!