From: Jiri Pirko <jiri@resnulli•us>
To: David Gibson <david@gibson•dropbear.id.au>
Cc: netdev@vger•kernel.org, ssujith@cisco•com, neepatel@cisco•com,
benve@cisco•com, davem@davemloft•net, ben@decadent•org.uk,
govindarajulu90@gmail•com, gregory.v.rose@intel•com
Subject: Re: [PATCH 2/2] rtnetlink: Only supply IFLA_VF_PORTS information when RTEXT_FILTER_VF is set
Date: Thu, 24 Apr 2014 17:51:06 +0200 [thread overview]
Message-ID: <20140424155106.GD2864@minipsycho.orion> (raw)
In-Reply-To: <1398298956-13084-3-git-send-email-david@gibson.dropbear.id.au>
Thu, Apr 24, 2014 at 02:22:36AM CEST, david@gibson•dropbear.id.au wrote:
>Since 115c9b81928360d769a76c632bae62d15206a94a (rtnetlink: Fix problem with
>buffer allocation), RTM_NEWLINK messages only contain the IFLA_VFINFO_LIST
>attribute if they were solicited by a GETLINK message containing an
>IFLA_EXT_MASK attribute with the RTEXT_FILTER_VF flag.
>
>That was done because some user programs broke when they received more data
>than expected - because IFLA_VFINFO_LIST contains information for each VF
>it can become large if there are many VFs.
>
>However, the IFLA_VF_PORTS attribute, supplied for devices which implement
>ndo_get_vf_port (currently the 'enic' driver only), has the same problem.
>It supplies per-VF information and can therefore become large, but it is
>not currently conditional on the IFLA_EXT_MASK value.
>
>Worse, it interacts badly with the existing EXT_MASK handling. When
>IFLA_EXT_MASK is not supplied, the buffer for netlink replies is fixed at
>NLMSG_GOODSIZE. If the information for IFLA_VF_PORTS exceeds this, then
>rtnl_fill_ifinfo() returns -EMSGSIZE on the first message in a packet.
>netlink_dump() will misinterpret this as having finished the listing and
>omit data for this interface and all subsequent ones. That can cause
>getifaddrs(3) to enter an infinite loop.
>
>This patch addresses the problem by only supplying IFLA_VF_PORTS when
>IFLA_EXT_MASK is supplied with the RTEXT_FILTER_VF flag set.
>
>Signed-off-by: David Gibson <david@gibson•dropbear.id.au>
Reviewed-by: Jiri Pirko <jiri@resnulli•us>
This should go to -net I believe.
next prev parent reply other threads:[~2014-04-24 15:51 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-04-24 0:22 [0/2] Fix problems with with IFLA_VF_PORTS (v2) David Gibson
2014-04-24 0:22 ` [PATCH 1/2] rtnetlink: Warn when interface's information won't fit in our packet David Gibson
2014-04-24 15:49 ` Jiri Pirko
2014-04-24 0:22 ` [PATCH 2/2] rtnetlink: Only supply IFLA_VF_PORTS information when RTEXT_FILTER_VF is set David Gibson
2014-04-24 15:51 ` Jiri Pirko [this message]
2014-04-24 17:53 ` [0/2] Fix problems with with IFLA_VF_PORTS (v2) David Miller
-- strict thread matches above, loose matches on Subject: below --
2014-04-23 7:21 [0/2] Fix problems with with IFLA_VF_PORTS David Gibson
2014-04-23 7:21 ` [PATCH 2/2] rtnetlink: Only supply IFLA_VF_PORTS information when RTEXT_FILTER_VF is set David Gibson
2014-04-23 9:17 ` Jiri Pirko
2014-04-24 0:13 ` David Gibson
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