From 71cc0873e0e0a4c6dca899c42e3ac143f7960d8e Mon Sep 17 00:00:00 2001 From: Phil Sutter Date: Tue, 3 Apr 2018 23:15:39 +0200 Subject: [PATCH] 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 --- include/net/netfilter/nf_tables.h | 36 +++---- net/netfilter/nf_tables_api.c | 25 ++--- net/netfilter/nft_set_bitmap.c | 34 +++---- net/netfilter/nft_set_hash.c | 157 ++++++++++++++++-------------- net/netfilter/nft_set_rbtree.c | 36 +++---- 5 files changed, 142 insertions(+), 146 deletions(-) diff --git a/include/net/netfilter/nf_tables.h b/include/net/netfilter/nf_tables.h index 123e82a2f8bb..de77d36e36b3 100644 --- a/include/net/netfilter/nf_tables.h +++ b/include/net/netfilter/nf_tables.h @@ -275,23 +275,6 @@ struct nft_set_estimate { enum nft_set_class space; }; -/** - * struct nft_set_type - nf_tables set type - * - * @select_ops: function to select nft_set_ops - * @ops: default ops, used when no select_ops functions is present - * @list: used internally - * @owner: module reference - */ -struct nft_set_type { - const struct nft_set_ops *(*select_ops)(const struct nft_ctx *, - const struct nft_set_desc *desc, - u32 flags); - const struct nft_set_ops *ops; - struct list_head list; - struct module *owner; -}; - struct nft_set_ext; struct nft_expr; @@ -310,7 +293,6 @@ struct nft_expr; * @init: initialize private data of new set instance * @destroy: destroy private data of set instance * @elemsize: element private size - * @features: features supported by the implementation */ struct nft_set_ops { bool (*lookup)(const struct net *net, @@ -361,10 +343,24 @@ struct nft_set_ops { void (*destroy)(const struct nft_set *set); unsigned int elemsize; - u32 features; - const struct nft_set_type *type; }; +/** + * struct nft_set_type - nf_tables set type + * + * @ops: set ops for this type + * @list: used internally + * @owner: module reference + * @features: features supported by the implementation + */ +struct nft_set_type { + const struct nft_set_ops ops; + struct list_head list; + struct module *owner; + u32 features; +}; +#define to_set_type(o) container_of(o, struct nft_set_type, ops) + int nft_register_set(struct nft_set_type *type); void nft_unregister_set(struct nft_set_type *type); diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 2f14cadd9922..9ce35acf491d 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -2523,14 +2523,12 @@ void nft_unregister_set(struct nft_set_type *type) EXPORT_SYMBOL_GPL(nft_unregister_set); #define NFT_SET_FEATURES (NFT_SET_INTERVAL | NFT_SET_MAP | \ - NFT_SET_TIMEOUT | NFT_SET_OBJECT) + NFT_SET_TIMEOUT | NFT_SET_OBJECT | \ + NFT_SET_EVAL) -static bool nft_set_ops_candidate(const struct nft_set_ops *ops, u32 flags) +static bool nft_set_ops_candidate(const struct nft_set_type *type, u32 flags) { - if ((flags & NFT_SET_EVAL) && !ops->update) - return false; - - return (flags & ops->features) == (flags & NFT_SET_FEATURES); + return (flags & type->features) == (flags & NFT_SET_FEATURES); } /* @@ -2567,14 +2565,9 @@ nft_select_set_ops(const struct nft_ctx *ctx, best.space = ~0; list_for_each_entry(type, &nf_tables_set_types, list) { - if (!type->select_ops) - ops = type->ops; - else - ops = type->select_ops(ctx, desc, flags); - if (!ops) - continue; + ops = &type->ops; - if (!nft_set_ops_candidate(ops, flags)) + if (!nft_set_ops_candidate(type, flags)) continue; if (!ops->estimate(desc, flags, &est)) continue; @@ -2605,7 +2598,7 @@ nft_select_set_ops(const struct nft_ctx *ctx, if (!try_module_get(type->owner)) continue; if (bops != NULL) - module_put(bops->type->owner); + module_put(to_set_type(bops)->owner); bops = ops; best = est; @@ -3247,14 +3240,14 @@ err3: err2: kvfree(set); err1: - module_put(ops->type->owner); + module_put(to_set_type(ops)->owner); return err; } static void nft_set_destroy(struct nft_set *set) { set->ops->destroy(set); - module_put(set->ops->type->owner); + module_put(to_set_type(set->ops)->owner); kfree(set->name); kvfree(set); } diff --git a/net/netfilter/nft_set_bitmap.c b/net/netfilter/nft_set_bitmap.c index 45fb2752fb63..d6626e01c7ee 100644 --- a/net/netfilter/nft_set_bitmap.c +++ b/net/netfilter/nft_set_bitmap.c @@ -296,27 +296,23 @@ static bool nft_bitmap_estimate(const struct nft_set_desc *desc, u32 features, return true; } -static struct nft_set_type nft_bitmap_type; -static struct nft_set_ops nft_bitmap_ops __read_mostly = { - .type = &nft_bitmap_type, - .privsize = nft_bitmap_privsize, - .elemsize = offsetof(struct nft_bitmap_elem, ext), - .estimate = nft_bitmap_estimate, - .init = nft_bitmap_init, - .destroy = nft_bitmap_destroy, - .insert = nft_bitmap_insert, - .remove = nft_bitmap_remove, - .deactivate = nft_bitmap_deactivate, - .flush = nft_bitmap_flush, - .activate = nft_bitmap_activate, - .lookup = nft_bitmap_lookup, - .walk = nft_bitmap_walk, - .get = nft_bitmap_get, -}; - static struct nft_set_type nft_bitmap_type __read_mostly = { - .ops = &nft_bitmap_ops, .owner = THIS_MODULE, + .ops = { + .privsize = nft_bitmap_privsize, + .elemsize = offsetof(struct nft_bitmap_elem, ext), + .estimate = nft_bitmap_estimate, + .init = nft_bitmap_init, + .destroy = nft_bitmap_destroy, + .insert = nft_bitmap_insert, + .remove = nft_bitmap_remove, + .deactivate = nft_bitmap_deactivate, + .flush = nft_bitmap_flush, + .activate = nft_bitmap_activate, + .lookup = nft_bitmap_lookup, + .walk = nft_bitmap_walk, + .get = nft_bitmap_get, + }, }; static int __init nft_bitmap_module_init(void) diff --git a/net/netfilter/nft_set_hash.c b/net/netfilter/nft_set_hash.c index fc9c6d5d64cd..dbf1f4ad077c 100644 --- a/net/netfilter/nft_set_hash.c +++ b/net/netfilter/nft_set_hash.c @@ -605,6 +605,12 @@ static void nft_hash_destroy(const struct nft_set *set) static bool nft_hash_estimate(const struct nft_set_desc *desc, u32 features, struct nft_set_estimate *est) { + if (!desc->size) + return false; + + if (desc->klen == 4) + return false; + est->size = sizeof(struct nft_hash) + nft_hash_buckets(desc->size) * sizeof(struct hlist_head) + desc->size * sizeof(struct nft_hash_elem); @@ -614,91 +620,100 @@ static bool nft_hash_estimate(const struct nft_set_desc *desc, u32 features, return true; } -static struct nft_set_type nft_hash_type; -static struct nft_set_ops nft_rhash_ops __read_mostly = { - .type = &nft_hash_type, - .privsize = nft_rhash_privsize, - .elemsize = offsetof(struct nft_rhash_elem, ext), - .estimate = nft_rhash_estimate, - .init = nft_rhash_init, - .destroy = nft_rhash_destroy, - .insert = nft_rhash_insert, - .activate = nft_rhash_activate, - .deactivate = nft_rhash_deactivate, - .flush = nft_rhash_flush, - .remove = nft_rhash_remove, - .lookup = nft_rhash_lookup, - .update = nft_rhash_update, - .walk = nft_rhash_walk, - .get = nft_rhash_get, - .features = NFT_SET_MAP | NFT_SET_OBJECT | NFT_SET_TIMEOUT, -}; - -static struct nft_set_ops nft_hash_ops __read_mostly = { - .type = &nft_hash_type, - .privsize = nft_hash_privsize, - .elemsize = offsetof(struct nft_hash_elem, ext), - .estimate = nft_hash_estimate, - .init = nft_hash_init, - .destroy = nft_hash_destroy, - .insert = nft_hash_insert, - .activate = nft_hash_activate, - .deactivate = nft_hash_deactivate, - .flush = nft_hash_flush, - .remove = nft_hash_remove, - .lookup = nft_hash_lookup, - .walk = nft_hash_walk, - .get = nft_hash_get, - .features = NFT_SET_MAP | NFT_SET_OBJECT, -}; - -static struct nft_set_ops nft_hash_fast_ops __read_mostly = { - .type = &nft_hash_type, - .privsize = nft_hash_privsize, - .elemsize = offsetof(struct nft_hash_elem, ext), - .estimate = nft_hash_estimate, - .init = nft_hash_init, - .destroy = nft_hash_destroy, - .insert = nft_hash_insert, - .activate = nft_hash_activate, - .deactivate = nft_hash_deactivate, - .flush = nft_hash_flush, - .remove = nft_hash_remove, - .lookup = nft_hash_lookup_fast, - .walk = nft_hash_walk, - .get = nft_hash_get, - .features = NFT_SET_MAP | NFT_SET_OBJECT, -}; - -static const struct nft_set_ops * -nft_hash_select_ops(const struct nft_ctx *ctx, const struct nft_set_desc *desc, - u32 flags) +static bool nft_hash_fast_estimate(const struct nft_set_desc *desc, u32 features, + struct nft_set_estimate *est) { - if (desc->size && !(flags & (NFT_SET_EVAL | NFT_SET_TIMEOUT))) { - switch (desc->klen) { - case 4: - return &nft_hash_fast_ops; - default: - return &nft_hash_ops; - } - } + if (!desc->size) + return false; - return &nft_rhash_ops; + if (desc->klen != 4) + return false; + + est->size = sizeof(struct nft_hash) + + nft_hash_buckets(desc->size) * sizeof(struct hlist_head) + + desc->size * sizeof(struct nft_hash_elem); + est->lookup = NFT_SET_CLASS_O_1; + est->space = NFT_SET_CLASS_O_N; + + return true; } -static struct nft_set_type nft_hash_type __read_mostly = { - .select_ops = nft_hash_select_ops, +static struct nft_set_type nft_rhash_type __read_mostly = { .owner = THIS_MODULE, + .features = NFT_SET_MAP | NFT_SET_OBJECT | + NFT_SET_TIMEOUT | NFT_SET_EVAL, + .ops = { + .privsize = nft_rhash_privsize, + .elemsize = offsetof(struct nft_rhash_elem, ext), + .estimate = nft_rhash_estimate, + .init = nft_rhash_init, + .destroy = nft_rhash_destroy, + .insert = nft_rhash_insert, + .activate = nft_rhash_activate, + .deactivate = nft_rhash_deactivate, + .flush = nft_rhash_flush, + .remove = nft_rhash_remove, + .lookup = nft_rhash_lookup, + .update = nft_rhash_update, + .walk = nft_rhash_walk, + .get = nft_rhash_get, + }, +}; + +static struct nft_set_type nft_hash_type __read_mostly = { + .owner = THIS_MODULE, + .features = NFT_SET_MAP | NFT_SET_OBJECT, + .ops = { + .privsize = nft_hash_privsize, + .elemsize = offsetof(struct nft_hash_elem, ext), + .estimate = nft_hash_estimate, + .init = nft_hash_init, + .destroy = nft_hash_destroy, + .insert = nft_hash_insert, + .activate = nft_hash_activate, + .deactivate = nft_hash_deactivate, + .flush = nft_hash_flush, + .remove = nft_hash_remove, + .lookup = nft_hash_lookup, + .walk = nft_hash_walk, + .get = nft_hash_get, + }, +}; + +static struct nft_set_type nft_hash_fast_type __read_mostly = { + .owner = THIS_MODULE, + .features = NFT_SET_MAP | NFT_SET_OBJECT, + .ops = { + .privsize = nft_hash_privsize, + .elemsize = offsetof(struct nft_hash_elem, ext), + .estimate = nft_hash_fast_estimate, + .init = nft_hash_init, + .destroy = nft_hash_destroy, + .insert = nft_hash_insert, + .activate = nft_hash_activate, + .deactivate = nft_hash_deactivate, + .flush = nft_hash_flush, + .remove = nft_hash_remove, + .lookup = nft_hash_lookup_fast, + .walk = nft_hash_walk, + .get = nft_hash_get, + }, }; static int __init nft_hash_module_init(void) { - return nft_register_set(&nft_hash_type); + if (nft_register_set(&nft_hash_fast_type) || + nft_register_set(&nft_hash_type) || + nft_register_set(&nft_rhash_type)) + return 1; + return 0; } static void __exit nft_hash_module_exit(void) { + nft_unregister_set(&nft_rhash_type); nft_unregister_set(&nft_hash_type); + nft_unregister_set(&nft_hash_fast_type); } module_init(nft_hash_module_init); 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)