i want just to add a comment: if you use the comlete stack, from emac driver to BSD socket, you will have ONLY one copy operation, on BSD interface. (..if we talk about full BSD compliance socket, but, i proposed in other mailing list, talking about future socket2, to have an option for using BSD socket without copy operation...)
Bye Piero 2009/2/13 bill <[email protected]> > In a nutshell, data going to and from the application is stored in memory > (either RAM or Flash). When the packet driver sends a packet, it sends the > payload part of the data from the same memory that the application provided > to be sent. When the packet driver receives data, the payload is passed to > the application in the same memory that it came in to from the MAC. There > can be significant improvement of program performance by not copying, > especially when sending or receiving lots of data. This is true from both > ends of the spectrum – low speed processors which take a lot of time to > simply copy memory and very high speed processors where a memory copy is > slow because of the relatively slow speed of memory and not because the > speed of the processor. > > > > Bill > > > > *From:* [email protected] [mailto: > lwip-users-bounces+bauerbach <lwip-users-bounces%2Bbauerbach>= > [email protected]] *On Behalf Of *Francois Bouchard > *Sent:* Friday, February 13, 2009 10:16 AM > *To:* Mailing list for lwIP users > *Subject:* Re: [lwip-users] Hello to mailinglist > > > > What exactly is zero-copy rx/tx? > > ----- Original Message ----- > > *From:* Piero 74 <[email protected]> > > *To:* Mailing list for lwIP users <[email protected]> > > *Sent:* Friday, February 13, 2009 9:52 AM > > *Subject:* Re: [lwip-users] Hello to mailinglist > > > > > > > > I suppose I can post it as a patch on savannah. I forgot, I also > developed a driver for the on-chip FEC+PHY of FreeScale's MCF5223x. It > does zero-copy receive. I'll post it as well, > > > please notify me after post... i want to see your implementation for > zero-copy > as you know we had some discussions in mailing list regarding zero-copy rx > and also zero-copy tx > > > > > But filtering IP > addresses and ports in the driver would be straightforward, wouldn't > it? Just match the appropriate fields from IP header against the > whitelist. > > > yes, i know... i also suppose is simple... > but i wanted to know if other people has developed a similar feature... > i know that is not a robust protection against hacking attack, but it could > mitagate them, > and it could be an interesting feature for the marketing (just label on the > box: "built-in firewall") > > thanks for your reply > bye > Piero > > > ------------------------------ > > _______________________________________________ > lwip-users mailing list > [email protected] > http://lists.nongnu.org/mailman/listinfo/lwip-users > > > _______________________________________________ > lwip-users mailing list > [email protected] > http://lists.nongnu.org/mailman/listinfo/lwip-users >
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