The conntrack label extension is currently variable-sized, e.g. if
only 2 labels are used by iptables rules then the labels->bits[] array
will only contain one element.
We track size of each label storage area in the 'words' member.
But in nftables and openvswitch we always have to ask for worst-case
since we don't know what bit will be used at configuration time.
As most arches are 64bit we need to allocate 24 bytes in this case:
struct nf_conn_labels {
u8 words; /* 0 1 */
/* XXX 7 bytes hole, try to pack */
long unsigned bits[2]; /* 8 24 */
Make bits a fixed size and drop the words member, it simplifies
the code and only increases memory requirements on x86 when
less than 64bit labels are required.
We still only allocate the extension if its needed.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
nf_connlabel_set() takes the bit number that we would like to set.
nf_connlabels_get() however took the number of bits that we want to
support.
So e.g. nf_connlabels_get(32) support bits 0 to 31, but not 32.
This changes nf_connlabels_get() to take the highest bit that we want
to set.
Callers then don't have to cope with a potential integer wrap
when using nf_connlabels_get(bit + 1) anymore.
Current callers are fine, this change is only to make folloup
nft ct label set support simpler.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
make the replace function only send a ctnetlink event if the contents
of the new set is different.
Otherwise 'ct label set ct label | bar'
will cause netlink event storm since we "replace" labels for each packet.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Currently labels can only be set either by iptables connlabel
match or via ctnetlink.
Before adding nftables set support, clean up the clabel core and move
helpers that nft will not need after all to the xtables module.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Add functions to change connlabel length into nf_conntrack_labels.c so
they may be reused by other modules like OVS and nftables without
needing to jump through xt_match_check() hoops.
Suggested-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Joe Stringer <joestringer@nicira.com>
Acked-by: Florian Westphal <fw@strlen.de>
Acked-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
The following patches will reuse this code from OVS.
Signed-off-by: Joe Stringer <joestringer@nicira.com>
Acked-by: Pravin B Shelar <pshelar@nicira.com>
Acked-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
commit 0ceabd8387
(netfilter: ctnetlink: deliver labels to userspace) sets the event bit
when we raced with another packet, instead of raising the event bit
when the label bit is set for the first time.
commit 9b21f6a909
(netfilter: ctnetlink: allow userspace to modify labels) forgot to update
the event mask in the "conntrack already exists" case.
Both issues result in CTA_LABELS attribute not getting included in the
conntrack event.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Move the global initial codes to the module_init/exit context.
Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Add the ability to set/clear labels assigned to a conntrack
via ctnetlink.
To allow userspace to only alter specific bits, Pablo suggested to add
a new CTA_LABELS_MASK attribute:
The new set of active labels is then determined via
active = (active & ~mask) ^ changeset
i.e., the mask selects those bits in the existing set that should be
changed.
This follows the same method already used by MARK and CONNMARK targets.
Omitting CTA_LABELS_MASK is the same as setting all bits in CTA_LABELS_MASK
to 1: The existing set is replaced by the one from userspace.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Introduce CTA_LABELS attribute to send a bit-vector of currently active labels
to userspace.
Future patch will permit userspace to also set/delete active labels.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
similar to connmarks, except labels are bit-based; i.e.
all labels may be attached to a flow at the same time.
Up to 128 labels are supported. Supporting more labels
is possible, but requires increasing the ct offset delta
from u8 to u16 type due to increased extension sizes.
Mapping of bit-identifier to label name is done in userspace.
The extension is enabled at run-time once "-m connlabel" netfilter
rules are added.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Florian Westphal