Re: [PATCH net-next 00/20] rtnetlink: Add support for rigid checking of data in dump request

[David Ahern <dsahern@gmail.com>]

On 10/4/18 3:33 PM, David Ahern wrote:
> From: David Ahern <dsahern@gmail.com>

...

> This patch set addresses the problem by adding a new socket flag,
> NETLINK_DUMP_STRICT_CHK, that userspace can use with setsockopt to
> request strict checking of headers and attributes on dump requests and
> hence unlock the ability to use kernel side filters as they are added.

...

> David Ahern (20):
>   netlink: Pass extack to dump handlers
>   netlink: Add extack message to nlmsg_parse for invalid header length
>   net: Add extack to nlmsg_parse
>   net/ipv6: Refactor address dump to push inet6_fill_args to
>     in6_dump_addrs
>   netlink: Add new socket option to enable strict checking on dumps
>   net/ipv4: Update inet_dump_ifaddr for strict data checking
>   net/ipv6: Update inet6_dump_addr for strict data checking
>   rtnetlink: Update rtnl_dump_ifinfo for strict data checking
>   rtnetlink: Update rtnl_bridge_getlink for strict data checking
>   rtnetlink: Update rtnl_stats_dump for strict data checking
>   rtnetlink: Update inet6_dump_ifinfo for strict data checking
>   rtnetlink: Update ipmr_rtm_dumplink for strict data checking
>   rtnetlink: Update fib dumps for strict data checking
>   net/neighbor: Update neigh_dump_info for strict data checking
>   net/neighbor: Update neightbl_dump_info for strict data checking
>   net/namespace: Update rtnl_net_dumpid for strict data checking
>   net/fib_rules: Update fib_nl_dumprule for strict data checking
>   net/ipv6: Update ip6addrlbl_dump for strict data checking
>   net: Update netconf dump handlers for strict data checking
>   net/bridge: Update br_mdb_dump for strict data checking
> 

One thing I missed in the rfc and v1 versions is strict attribute
parsing -- ie., there should be nothing remaining after nla_parse is
done. I have a new patch that adds an nlmsg_parse_strict and
nla_parse_strict that returns -EINVAL (with extack filled in) if that
happens. The new patch pushes the set over 20.

I can peel off the first 3 patches from this set which add extack to the
dumps and down to nlmsg_parse and send those separately if preferred.