Dudes, thanks for the book reference. i go to Borders fora copy myself. Is it OSI 8 mounth that that eats the osi7 layer buritto, like the ones you get down in Jose's Burrito Shack. foot of HMmmmmm good! ---- Original Message ---- From: Valdis.Kletnieks@vt.edu To: billcu@citynet.net Subject: Re: TCP/IP Date: Mon, 27 May 2002 10:38:13 -0400 >On Mon, 27 May 2002 09:38:12 EDT, Bill Cunningham ><billcu@citynet.net> said: >> Win98 is what I use mostly I also have linux. Your right I'd like >to enter > >For Linux, you have the source - go poke around in >/usr/src/linux/drivers/net >which contains the bottom half of the stack (the device drivers). >The >top half, which does protocol support, is under /usr/src/linux/net/*. > >Please note that from userspace, you want to be using the provided >syscalls, >as you will most certainly generate an error if you go calling >kernel code >without a firm understanding of what you're trying to do and why. > >I'd certainly stay *FAR* away from any system's TCP stack internals >until >I had read *and understood* at least the first volume or two of >Comer's books, >and for Unix/Linux, Steven's "Unix Network Programming". If you >don't >recognize those 2 references, you're not ready. ;) > >I think you're getting confused by terminology - although many >programs >have their function entry points on a "stack", which is vulnerable to >tweaking by buffer overflows and other malware, the entire networking >subsystem is *also* referred to as a "stack" (which makes sense once >you >understand the basics of the OSI 7-layer burrito^H^H^H^H^Hmodel). >As such, >the networking code doesn't really *HAVE* a distinct entry point - >it's being >called many ways for different things - from userspace via the >syscall >interface (to open/bind/send/receive/close a connection), to/from >device >drivers to receive packets and queue packets for transmission, hooks >into >the system timing services for callbacks to maintain retransmit >timers, >and so on. > >-- > Valdis Kletnieks > Computer Systems Senior Engineer > Virginia Tech > >