Re: [lwip-users] netconn_recv issue

[David Empson]

----- Original Message ----- 
From: "am85" <address@hidden>
To: <address@hidden>
Sent: Thursday, August 26, 2010 8:29 PM
Subject: Re: [lwip-users] netconn_recv issue


> Hi Kieran,
> Thank you very much.
>
> I'm trying to implement this code, but I have the same problem.
>
> do
> {
>  netbuf_data(Buffer, (void *) &dataptr, &len);
>  data = dataptr;
>
> if( strncmp(data, "GET / ", 4 ) == 0 )
> {
>        /* Send home page: text only */
>        netconn_write( RxConn, (char *)(file.data), file.len, NETCONN_COPY
> );

The above strncmp is a problem. If you only compare 4 characters, this will 
match every data item starting with "GET" followed by a single space. This 
will intercept all GET statements, not just "GET /".

Even if you increased the length to 5, it won't help, because it will still 
match all GET statements with a pathname starting with a slash.

You also need to confirm that there is no more text after the forward slash, 
and in order to do that you need to detect the end of the HTTP request as 
you might not have received all of it yet.

> }
>
>  else if( strncmp(data, "GET /image1.gif", 15 ) == 0 )
> {
>        /* Send first picture */
>        netconn_write( RxConn, (char *)(file.data), file.len, NETCONN_COPY
> );
> }
>
> else if( strncmp(data, "GET /image2.gif", 15 ) == 0 )
> {
>        /* Send second picture */
>        netconn_write( RxConn, (char *)(file.data), file.len, NETCONN_COPY
> );
> }
> } while(netbuf_next(Buffer) == -1);
>
>
> Thanks to the previous answers.
>
> With regards,
> am85