Re: Window shrinking (was Linux v2.6.16-rc6)

2006-04-10 Thread Mark Butler
Andy Furniss wrote: Mark Butler wrote: There is no problem manipulating the TCP window per se. The problem is advertising a window and then shrinking it faster than it is naturally reduced by incoming data, essentially granting credit to transmit x bytes, and then revoking that credit

Re: Window shrinking (was Linux v2.6.16-rc6)

2006-04-10 Thread Mark Butler
Andy Furniss wrote: Mark Butler wrote: Andy Furniss wrote: Mark Butler wrote: There is no problem manipulating the TCP window per se. The problem is advertising a window and then shrinking it faster than it is naturally reduced by incoming data, essentially granting credit to transmit x

Re: Window shrinking (was Linux v2.6.16-rc6)

2006-04-09 Thread Mark Butler
Andy Furniss wrote: David S. Miller wrote: From: Michal Piotrowski [EMAIL PROTECTED] Date: Sun, 12 Mar 2006 02:51:40 +0100 I have noticed this warnings TCP: Treason uncloaked! Peer 82.113.55.2:11759/50967 shrinks window 148470938:148470943. Repaired. TCP: Treason uncloaked! Peer

Re: [PATCH] net: Broadcast ARP packets on link local addresses

2006-04-07 Thread Mark Butler
jamal wrote: On Fri, 2006-07-04 at 17:20 +1000, Anand Kumria wrote: On Fri, 31 Mar 2006 15:26:00 -0800, David Daney wrote: From: David Daney Greetings, When an internet host joins a network where there is no DHCP server, it may auto-allocate an IP address by the method described in

Re: [PATCH] net: Broadcast ARP packets on link local addresses

2006-04-07 Thread Mark Butler
Mark Butler wrote: jamal wrote: On Fri, 2006-07-04 at 17:20 +1000, Anand Kumria wrote: On Fri, 31 Mar 2006 15:26:00 -0800, David Daney wrote: From: David Daney Greetings, When an internet host joins a network where there is no DHCP server, it may auto-allocate an IP address

Re: Broadcast ARP packets on link local addresses (Version2).

2006-04-07 Thread Mark Butler
David Daney wrote: Following your logic through, It seems that you are advocating broadcasting *all* ARP packets on *all* link local addresses. That would mean that on a 192.168.* switched Ethernet network with DHCP that twice as many ARP packets would be broadcast. 192.168.* addresses are

Re: Question about skb clones and frag_list

2006-04-05 Thread Mark Butler
Vlad Yasevich wrote: On Wed, 2006-04-05 at 10:38 -0600, Mark Butler wrote: The problem in this case is skb1 does not own the skb_shared_info structure (and hence the frag_list) once it has been cloned. skb_unshare is the function that should be used to get a modifiable copy. So

Re: magical 552 mtu

2006-04-04 Thread Mark Butler
Rick Jones wrote: Again from RFC 791: snip Every internet destination must be able to receive a datagram of 576 octets either in one piece or in fragments to be reassembled. Hence the minimum IPv4 MTU of 68 bytes. Makes sense to me. Does a similar argument apply the IPv6 minimum

Re: [Bugme-new] [Bug 6309] New: SO_RCVBUF doubled on set not halved on get

2006-03-31 Thread Mark Butler
Bill Fink wrote: Another reason the SO_SNDBUF/SO_RCVBUF values shouldn't include the kernel overhead. If the user requests 100K of kernel data buffering, then they should get 100K. It shouldn't matter to the user that the kernel would actually be using a total of 167K of memory to satisfy

Re: [Bugme-new] [Bug 6309] New: SO_RCVBUF doubled on set not halved on get

2006-03-30 Thread Mark Butler
David S. Miller wrote: This has been this way for centuries and it's the correct behavior. We double it on the way in to account for struct sk_buff etc. overhead, applications assume that the SO_RCVBUF setting they make will allow that much actual data to be received on that socket.

Re: Output packet processing (was stretch ACKs, etc.)

2006-03-26 Thread Mark Butler
Andi Kleen wrote: On Saturday 25 March 2006 23:32, Mark Butler wrote: A true firewall should never need to do anything but drop packets and reset connections. Changes to the way packets are routed should be done at the routing layer, using the flow information from the transport layer

Re: Output packet processing (was stretch ACKs, etc.)

2006-03-25 Thread Mark Butler
David S. Miller wrote: From: Mark Butler [EMAIL PROTECTED] Date: Fri, 24 Mar 2006 22:37:26 -0700 On a more general note, I find the idea that a current dst entry doesn't actually reflect the interface (even a logical interface) and nexthop that will be used to deliver a packet a little

Re: Stretch ACKs, etc. (was TSO and IPoIB performance degradation)

2006-03-24 Thread Mark Butler
Wouldn't the appropriate place to add the tunable for Stretch ACKs be as a route attribute similar to RTAX_ADVMSS? Then system administrators who are aware of the local network topology, netfilters, etc, could use an ip route or whatever command to enable it on the route entry for the

Re: [openib-general] Re: [iproute2] IPoIB link layer address bug

2006-03-23 Thread Mark Butler
Mark Butler wrote: James Lentini wrote: On Tue, 21 Mar 2006, Jason Gunthorpe wrote: On Tue, Mar 21, 2006 at 03:56:17PM -0800, Stephen Hemminger wrote: Okay, but there are number of other places in iproute2 that call ll_addr_a2n() with ifr.ifr_hwaddr.sa_data. And that is 14 bytes

Re: Writing a rate based transport protocol

2006-03-22 Thread Mark Butler
Stephen Hemminger wrote: The bigger problem is that too be effective rate control needs accurate real time. Linux is doing better at real time, but still providing useful high speed inter packet spacing is beyond the current capabilities. To get around this I think most high speed 10G cards

Re: Writing a rate based transport protocol

2006-03-22 Thread Mark Butler
Ian McDonald wrote: On 3/23/06, Mark Butler [EMAIL PROTECTED] wrote: I understand that timed intervals between individual packets is not realistic in general. What I have in mind is a fixed granularity transmission timer, where packets are assigned to buckets, and transmitted one bucket

Re: ES-API

2006-03-21 Thread Mark Butler
On Mon Mar 14, 2006, Christopher Hellwig wrote: On Mon, Mar 13, 2006 at 02:25:08PM -0800, Zach Brown wrote: Hi guys, I'm hearing noise about the 'Extended Sockets' API in Oracle. It's an extension to the socket API put together by an industry group that calls itself the Interconnect

Re: shared abstractions (was Writing a rate based transport protocol)

2006-03-21 Thread Mark Butler
One Tue, 14 Mar 2006 11:37:38 -0300, Arnaldo Carvalho de Melo wrote: On 3/13/06, Saurabh Jain [EMAIL PROTECTED] wrote: Hi All, I am trying to write a new rate based transport protocol in linux kernel (either as a module or directly within the kernel). Basically it

Re: Writing a rate based transport protocol

2006-03-21 Thread Mark Butler
On Mon, 13 Mar 2006 18:20:26 -0600, Saurabh Jain wrote: Hi All, I am trying to write a new rate based transport protocol in linux kernel (either as a module or directly within the kernel). Basically it would be similar to UDP but with features like dynamic rate control, connection

XFRM SCTP support

2006-03-20 Thread Mark Butler
The XFRM code base looks like it needs a relatively intrusive change to support protocols like SCTP correctly. The problem is that security policies are cached on the socket level, where SCTP not only uses multiple addresses per association, but multiple associations per socket. I believe