[ofw] [PATCH] ipoib_ndis6_cm - prevent UD IPoIB from falsely advertizing a Connect Mode capability.

[Alex Naslednikov]

Oh...please, commit ! 
But in the future, when CM mode will be released, the code should be like:
ipoib_addr_set_flags( &p_ib_arp->src_hw, p_port->p_adapter->params.cm_enabled ? IPOIB_CM_FLAG_RC : 0 );

-----Original Message-----
From: Smith, Stan [mailto:stan.smith at intel.com] 
Sent: Monday, September 13, 2010 10:47 PM
To: Alex Naslednikov
Cc: ofw at lists.openfabrics.org
Subject: [PATCH] ipoib_ndis6_cm - prevent UD IPoIB from falsely advertizing a Connect Mode capability.


Hello,
  Here is a curious bug for your inspection.
In the case where a UD [non-CM (Connected Mode)] IPoIB receives an ARP Request from a CM enabled IPoIB, the UD IPoIB can falsely advertise a CM (Connect Mode) capability in the ARP Reply src hardware address due to an uninitialized CM flags field.
The ARP reply packet is constructed from a send_buf_list allocated buffer. The cm field byte of the src hardware address in the ARP Request never gets initialized, hence the IPoIB UD ARP reply can falsely advertise a CM capability depending on the value of the CM capability byte; turns out 1 is a somewhat common memory value. :-) It's not a problem for UD IPoIB talking to another UD IPoIB; CM flags are ignored.
OFED/Linux CM IPoIB would attempt to RC connect which would fail.

The fix is to always set the CM capabilities byte of the ARP Reply src hardware address.flags_qpn field with the current IPoIB CM capability byte.

signed-off-by: stan smith <stan.smith at intel.com>

--- a/ulp/ipoib_NDIS6_CM/kernel/ipoib_port.cpp  Mon Sep 13 13:08:48 2010
+++ b/ulp/ipoib_NDIS6_CM/kernel/ipoib_port.cpp  Mon Sep 13 11:18:39 2010
@@ -4891,6 +4891,7 @@
        p_ib_arp->op = p_arp->op;

        ipoib_addr_set_qpn( &p_ib_arp->src_hw, s_buf->p_port->ib_mgr.qpn );
+       ipoib_addr_set_flags( &p_ib_arp->src_hw, 0 );
 #if 0

        if( p_port->p_adapter->params.cm_enabled )