| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
We get a partial cache (tables, chains and sets) when:
* We see a set reference from a rule, since this set object may be
already defined in kernelspace and we need to fetch the datatype
for evaluation.
* We add/delete a set element, we need this to evaluate if the
element datatype is correct.
* We rename a chain, since we need to know the chain handle.
* We add a chain/set. This isn't needed for simple command line
invocations. However, since the existing codepath is also exercised
from `nft -f' context, we need to know if the object exists in the
kernel. Thus, if this a newly declared object (not yet in the kernel) we
add it to the cache, otherwise, we will not find follow up references to
this object in our cache.
We get a full cache when:
* We list the ruleset. We can provide finer grain listing though,
via partial cache, later.
* We monitor updates, since this displays incremental updates based on
the existing objects.
* We export the ruleset, since this dumps all of the existing objects.
* We push updates via `nft -f'. We need to know what objects are
already in the kernel for incremental updates. Otherwise,
cache_update() hits a bogus 'set doesn't exist' error message for
just declared set in this batch. To avoid this problem, we need a
way to differentiate between what objects in the lists that are
already defined in the kernel and what are just declared in this
batch (hint: the location structure information is set for just
declared objects).
We don't get a cache at all when:
* We flush the ruleset, this is important in case of delinearize
bugs, so you don't need to reboot or manually flush the ruleset via
libnftnl examples/nft-table-flush.
* We delete any object, except for set elements (as we describe above).
* We add a rule, so you can generate via --debug=netlink the expression
without requiring a table and chain in place.
* We describe a expression.
This patch also includes some intentional adjustments to the shell tests
to we don't get bogus errors due to changes in the list printing.
BTW, this patch also includes a revert for 97493717e738 ("evaluate: check
if table and chain exists when adding rules") since that check is not
possible anymore with this logic.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
|
