RE: [lwip-users] CGI - Porting uIP webserver app (httpd-cgi.c) to lwIP?

[Ed Sutton]

Hi Bill,

 

Yes, I agree using GET would be much simpler  to set parameters on my embedded device as compared to trying to implement POST. 

 

I had visions of creating my web pages by cloning the web page source code of of a Linksys or Netgear device and then hack it up to fit my application.  I notice that there is a lot of _javascript_ in the Netgear web pages.  However,  at this point, the path of least resistance is probably a good approach.

 

Thank you *very much* for the link to the GET and POST overviews.  I really needed that as I have not paid too much attention to web development and never implemented an embedded web server.

 

Thanks again,

 

-Ed

 

From: address@hidden [mailto:address@hidden On Behalf Of Bill Auerbach
Sent: Monday, February 23, 2009 3:25 PM
To: 'Mailing list for lwIP users'
Subject: RE: [lwip-users] CGI - Porting uIP webserver app (httpd-cgi.c) to lwIP?

 

Hi Ed,

 

I would use GET for this – it’s much simpler as the data you want to get to is in the HTTP headers which is easy to parse since it follows the GET.

 

2 years ago Frédéric BERNON posted this: http://lists.gnu.org/archive/html/lwip-users/2007-07/msg00057.html.  It’s a great short description of GET and POST.

 

Bill

 

From: address@hidden [mailto:address@hidden On Behalf Of Ed Sutton
Sent: Monday, February 23, 2009 3:56 PM
To: Mailing list for lwIP users
Subject: RE: [lwip-users] CGI - Porting uIP webserver app (httpd-cgi.c) to lwIP?

 

Hi Bill,

 

Thank you for the warning as I was not aware.

 

If I can figure out how to use it to POST updates to my embedded device, for example to set a new static IP from a simple web page, I think I will have what I need.  So far it appears that CGI only supports GET.  The SSI includes work well enough though for displaying device status on a web page.

 

I found this searching for 0x20000000:

 

         /* If the data is being read from a buffer in RAM, we need to copy it

         * into the PCB. If it's in flash, however, we can avoid the copy since

         * the data is obviously not going to be overwritten during the life

         * of the connection.

         */

         err = tcp_write(pcb, hs->file, len,   (hs->file < (char *)0x20000000) ? 0 : 1);

 

Thanks again,

 

-Ed

 

From: address@hidden [mailto:address@hidden On Behalf Of Bill Auerbach
Sent: Monday, February 23, 2009 2:47 PM
To: 'Mailing list for lwIP users'
Subject: RE: [lwip-users] CGI - Porting uIP webserver app (httpd-cgi.c) to lwIP?

 

Be careful of the system dependency that is hard coded in the source code about the location of flash and RAM.  Search for 0x20000000.

Bill

>That looks perfect. The Adam Dunkel version of httpd.c had been modified by

>Luminary Micro to offer simple server-side-include (SSI) and Common Gateway

>Interface (CGI) capability.  Exactly what I needed for basic setup and status

>of my device.  Thank you very much for taking the time to send me this detailed

>information!