From 71cc0873e0e0a4c6dca899c42e3ac143f7960d8e Mon Sep 17 00:00:00 2001 From: Phil Sutter Date: Tue, 3 Apr 2018 23:15:39 +0200 Subject: netfilter: nf_tables: Simplify set backend selection Drop nft_set_type's ability to act as a container of multiple backend implementations it chooses from. Instead consolidate the whole selection logic in nft_select_set_ops() and the actual backend provided estimate() callback. This turns nf_tables_set_types into a list containing all available backends which is traversed when selecting one matching userspace requested criteria. Also, this change allows to embed nft_set_ops structure into nft_set_type and pull flags field into the latter as it's only used during selection phase. A crucial part of this change is to make sure the new layout respects hash backend constraints formerly enforced by nft_hash_select_ops() function: This is achieved by introduction of a specific estimate() callback for nft_hash_fast_ops which returns false for key lengths != 4. In turn, nft_hash_estimate() is changed to return false for key lengths == 4 so it won't be chosen by accident. Also, both callbacks must return false for unbounded sets as their size estimate depends on a known maximum element count. Note that this patch partially reverts commit 4f2921ca21b71 ("netfilter: nf_tables: meter: pick a set backend that supports updates") by making nft_set_ops_candidate() not explicitly look for an update callback but make NFT_SET_EVAL a regular backend feature flag which is checked along with the others. This way all feature requirements are checked in one go. Signed-off-by: Phil Sutter Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nft_set_rbtree.c | 36 ++++++++++++++++-------------------- 1 file changed, 16 insertions(+), 20 deletions(-) (limited to 'net/netfilter/nft_set_rbtree.c') diff --git a/net/netfilter/nft_set_rbtree.c b/net/netfilter/nft_set_rbtree.c index e6f08bc5f359..22c57d7612c4 100644 --- a/net/netfilter/nft_set_rbtree.c +++ b/net/netfilter/nft_set_rbtree.c @@ -393,28 +393,24 @@ static bool nft_rbtree_estimate(const struct nft_set_desc *desc, u32 features, return true; } -static struct nft_set_type nft_rbtree_type; -static struct nft_set_ops nft_rbtree_ops __read_mostly = { - .type = &nft_rbtree_type, - .privsize = nft_rbtree_privsize, - .elemsize = offsetof(struct nft_rbtree_elem, ext), - .estimate = nft_rbtree_estimate, - .init = nft_rbtree_init, - .destroy = nft_rbtree_destroy, - .insert = nft_rbtree_insert, - .remove = nft_rbtree_remove, - .deactivate = nft_rbtree_deactivate, - .flush = nft_rbtree_flush, - .activate = nft_rbtree_activate, - .lookup = nft_rbtree_lookup, - .walk = nft_rbtree_walk, - .get = nft_rbtree_get, - .features = NFT_SET_INTERVAL | NFT_SET_MAP | NFT_SET_OBJECT, -}; - static struct nft_set_type nft_rbtree_type __read_mostly = { - .ops = &nft_rbtree_ops, .owner = THIS_MODULE, + .features = NFT_SET_INTERVAL | NFT_SET_MAP | NFT_SET_OBJECT, + .ops = { + .privsize = nft_rbtree_privsize, + .elemsize = offsetof(struct nft_rbtree_elem, ext), + .estimate = nft_rbtree_estimate, + .init = nft_rbtree_init, + .destroy = nft_rbtree_destroy, + .insert = nft_rbtree_insert, + .remove = nft_rbtree_remove, + .deactivate = nft_rbtree_deactivate, + .flush = nft_rbtree_flush, + .activate = nft_rbtree_activate, + .lookup = nft_rbtree_lookup, + .walk = nft_rbtree_walk, + .get = nft_rbtree_get, + }, }; static int __init nft_rbtree_module_init(void) -- cgit