Re: [ECOS] Re: Improving TFTP performance

[Andrew Lunn <andrew@lunn.ch>]

On Wed, Dec 19, 2007 at 11:38:22AM +0100, ?yvind Harboe wrote:
> Take #2. Wrote up negotiation of segsize, passes first smoketest.
> Anyone interesting helping to test/comment on the patch?
> 
> Tested w/this server: http://tftpd32.jounin.net
> 
> -- 
> ?yvind Harboe
> http://www.zylin.com - eCos ARM & FPGA  developer kit

> ### Eclipse Workspace Patch 1.0
> #P ecos
> Index: net/common/current/cdl/net.cdl
> ===================================================================
> RCS file: /cvs/ecos/ecos-opt/net/net/common/current/cdl/net.cdl,v
> retrieving revision 1.17
> diff -u -r1.17 net.cdl
> --- net/common/current/cdl/net.cdl	7 Jan 2007 14:46:55 -0000	1.17
> +++ net/common/current/cdl/net.cdl	19 Dec 2007 10:36:38 -0000
> @@ -167,6 +167,16 @@
>              threads can have precedence over TFTP server processing."
>          }
>  
> +        cdl_option CYGPKG_NET_TFTPD_CLIENT_GET_PACKETSIZE {
> +            display "TFTP protocol allows negotiation of bigger packets."
> +            flavor  data
> +            default_value 512
> +            legal_values 512 to 65464
> +            description   "
> +             tftp blksize egotiation support. >512 byte block sizes improves 
> +             tftp GET performance"
> +        }

You should comment that this requires a server which implements the
optional RFC 2348.

> +	    if (ntohs(hdr->th_opcode) == OACK) {
> +	    	// We can have only *one* option, the one we sent..
> +	    	if (strncmp(data+2, "blksize", from_len)==0)
> +	    	{
> +	    		blksize=atol(data+2+strlen("blksize")+1);
> +	    	} else
> +	    	{
> +	    		// option ignored, use default.
> +	    	}
> +		      // Send out the ACK
> +		      hdr->th_opcode = htons(ACK);
> +		      hdr->th_block = htons(last_good_block);
> +		      if (sendto(s, data, 4 /* FIXME */, 0, 
> +				 &from_addr, from_len) < 0) {
> +			// Problem sending request
> +			*err = TFTP_NETERR;
> +			goto out;
> +		      }
> +		      
> +	    } 

This should be conditionally compiled. 

> +		    int * const err) {
> +	int result;
> +#if CYGPKG_NET_TFTPD_CLIENT_GET_PACKETSIZE>512
> +    char *data = malloc(CYGPKG_NET_TFTPD_CLIENT_GET_PACKETSIZE+sizeof(struct tftphdr));

No lines longer than 80 characters please.

You probably need to look at the case of the server returning ERROR
when you pass it the additional option during a get. You probably
should try the GET again without the option and see if it works.

       Andrew


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