linux-stable/net/netlink
Pablo Neira e1ee3673a8 genetlink: fix usage of NLM_F_EXCL or NLM_F_REPLACE
Currently, it is not possible to use neither NLM_F_EXCL nor
NLM_F_REPLACE from genetlink. This is due to this checking in
genl_family_rcv_msg:

	if (nlh->nlmsg_flags & NLM_F_DUMP)

NLM_F_DUMP is NLM_F_MATCH|NLM_F_ROOT. Thus, if NLM_F_EXCL or
NLM_F_REPLACE flag is set, genetlink believes that you're
requesting a dump and it calls the .dumpit callback.

The solution that I propose is to refine this checking to
make it stricter:

	if ((nlh->nlmsg_flags & NLM_F_DUMP) == NLM_F_DUMP)

And given the combination NLM_F_REPLACE and NLM_F_EXCL does
not make sense to me, it removes the ambiguity.

There was a patch that tried to fix this some time ago (0ab03c2
netlink: test for all flags of the NLM_F_DUMP composite) but it
tried to resolve this ambiguity in *all* existing netlink subsystems,
not only genetlink. That patch was reverted since it broke iproute2,
which is using NLM_F_ROOT to request the dump of the routing cache.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-07-30 16:43:19 -07:00
..
af_netlink.c netlink: fix splat in skb_clone with large messages 2013-06-27 22:44:16 -07:00
af_netlink.h netlink: Add compare function for netlink_table 2013-06-11 02:39:42 -07:00
diag.c netlink: Fix build with mmap disabled. 2013-04-23 15:39:03 -04:00
genetlink.c genetlink: fix usage of NLM_F_EXCL or NLM_F_REPLACE 2013-07-30 16:43:19 -07:00
Kconfig netlink: kconfig: move mmap i/o into netlink kconfig 2013-05-01 15:02:42 -04:00
Makefile netlink: Diag core and basic socket info dumping (v2) 2013-03-21 12:38:03 -04:00