httpd server crashes if unhandled POST data > 1 chunk

[phatpaul]

If I send POST data to the server and there is no cgi function configured to handle it, it crashes horribly.

To repeat: Send post data with cURL

$ curl --progress-bar -X POST -T bigfile.txt "http://192.168.33.173/newdir/test.txt" | tee /dev/null
#                                                                          2.0%
404 File not found.

E (6827) httpd: url = NULL
E (6827) httpd: Unexpected data from client. blah blah blah........
... pages of error...
E (6827) httpd: Unexpected data from client. blah blah blah........
... pages of error...
... repeats indefinitely ...

I fixed it by adding a check to cgiNotFound() that continues if post data has not been completely received.

//Used to spit out a 404 error
static CgiStatus ICACHE_FLASH_ATTR cgiNotFound(HttpdConnData *connData) {
    if (connData->isConnectionClosed) return HTTPD_CGI_DONE;
    if (connData->post.received == connData->post.len)
    {
        httpdStartResponse(connData, 404);
        httpdEndHeaders(connData);
        httpdSend(connData, "404 File not found.", -1);
        return HTTPD_CGI_DONE;
    }
    return HTTPD_CGI_MORE; // make sure to eat-up all the post data that the client may be sending!
}

Also, I prevented that (and other?) error from repeating indefintely by adding a break; after it.

Philosophically, should the server continue to eat-up all of the post data if it can't do anything with it? The file could be gigabytes and used as a DoS attack. Is there a way to gracefully refuse the post?

Stay tuned for pull-request.