On Tue, 2006-12-05 at 19:31 +0300, Evgeniy Polyakov wrote: > On Tue, Dec 05, 2006 at 10:12:42AM -0600, Steve Wise ([EMAIL PROTECTED]) > wrote: > > Ah. Data from an offloaded connection cannot leak into the main stack > > nor vice-verse. We can take an active RDMA connection establishment as > > an example if you want: Once the message is sent to the HW to "setup a > > TCP connection from addr/port a.b to addr/port c.d", then packets on > > that connection (that 4-tuple) will always be delivered to the RDMA > > driver, not the native stack. If the the packet received after the > > connection is setup is -not- an MPA reply (in this example), then the > > connection is aborted. Once the connection is aborted. So no leaking > > can happen. > > And if there were a dataflow between addr/port a.b to addr/port c.d > already, it will either terminated? > > Considering the following sequence: > handlers->t3c_handlers->sched()->work_queue->work_handlers()->for > example CPL_PASS_ACCEPT_REQ->pass_accept_req() - it just parses incoming > skb and sets port/addr/route and other fields to be used as a base for rdma > connection. What if it just a usual network packet from kernelspace or > userspace with the same payload as should be sent by remote rdma system? >
That skb isn't a network packet. Its a CPL_PASS_ACCEPT_REQ message (see struct cpl_pass_accept_req in the Ethernet driver t3_cpl.h). If the RDMA driver hadn't registered to listen on that addr/port, it would never get this skb. Once a connection is established, the MPA messages (and any TCP payload data) is delivered to the RDMA driver in the form of skb's containing struct cpl_rx_data. So these skbs aren't just TCP packets at all. They either control messages or TCP payload. Either way they are encapsulated in CPL message structures. Does this make sense? - To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
