diff options
author | Pablo Neira Ayuso <pablo@netfilter.org> | 2017-10-09 20:52:28 +0300 |
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committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2017-11-07 03:00:31 +0300 |
commit | ba0e4d9917b43dfa746cbbcb4477da59aae73bd6 (patch) | |
tree | b8665d2f2be0764277f19fb0a45c59dff4650259 /net/netfilter/nft_set_rbtree.c | |
parent | 644e334eeec01a25138b62ebd576b3a798183c7c (diff) | |
download | linux-ba0e4d9917b43dfa746cbbcb4477da59aae73bd6.tar.xz |
netfilter: nf_tables: get set elements via netlink
This patch adds a new get operation to look up for specific elements in
a set via netlink interface. You can also use it to check if an interval
already exists.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'net/netfilter/nft_set_rbtree.c')
-rw-r--r-- | net/netfilter/nft_set_rbtree.c | 73 |
1 files changed, 73 insertions, 0 deletions
diff --git a/net/netfilter/nft_set_rbtree.c b/net/netfilter/nft_set_rbtree.c index d83a4ec5900d..e6f08bc5f359 100644 --- a/net/netfilter/nft_set_rbtree.c +++ b/net/netfilter/nft_set_rbtree.c @@ -113,6 +113,78 @@ static bool nft_rbtree_lookup(const struct net *net, const struct nft_set *set, return ret; } +static bool __nft_rbtree_get(const struct net *net, const struct nft_set *set, + const u32 *key, struct nft_rbtree_elem **elem, + unsigned int seq, unsigned int flags, u8 genmask) +{ + struct nft_rbtree_elem *rbe, *interval = NULL; + struct nft_rbtree *priv = nft_set_priv(set); + const struct rb_node *parent; + const void *this; + int d; + + parent = rcu_dereference_raw(priv->root.rb_node); + while (parent != NULL) { + if (read_seqcount_retry(&priv->count, seq)) + return false; + + rbe = rb_entry(parent, struct nft_rbtree_elem, node); + + this = nft_set_ext_key(&rbe->ext); + d = memcmp(this, key, set->klen); + if (d < 0) { + parent = rcu_dereference_raw(parent->rb_left); + interval = rbe; + } else if (d > 0) { + parent = rcu_dereference_raw(parent->rb_right); + } else { + if (!nft_set_elem_active(&rbe->ext, genmask)) + parent = rcu_dereference_raw(parent->rb_left); + + if (!nft_set_ext_exists(&rbe->ext, NFT_SET_EXT_FLAGS) || + (*nft_set_ext_flags(&rbe->ext) & NFT_SET_ELEM_INTERVAL_END) == + (flags & NFT_SET_ELEM_INTERVAL_END)) { + *elem = rbe; + return true; + } + return false; + } + } + + if (set->flags & NFT_SET_INTERVAL && interval != NULL && + nft_set_elem_active(&interval->ext, genmask) && + !nft_rbtree_interval_end(interval)) { + *elem = interval; + return true; + } + + return false; +} + +static void *nft_rbtree_get(const struct net *net, const struct nft_set *set, + const struct nft_set_elem *elem, unsigned int flags) +{ + struct nft_rbtree *priv = nft_set_priv(set); + unsigned int seq = read_seqcount_begin(&priv->count); + struct nft_rbtree_elem *rbe = ERR_PTR(-ENOENT); + const u32 *key = (const u32 *)&elem->key.val; + u8 genmask = nft_genmask_cur(net); + bool ret; + + ret = __nft_rbtree_get(net, set, key, &rbe, seq, flags, genmask); + if (ret || !read_seqcount_retry(&priv->count, seq)) + return rbe; + + read_lock_bh(&priv->lock); + seq = read_seqcount_begin(&priv->count); + ret = __nft_rbtree_get(net, set, key, &rbe, seq, flags, genmask); + if (!ret) + rbe = ERR_PTR(-ENOENT); + read_unlock_bh(&priv->lock); + + return rbe; +} + static int __nft_rbtree_insert(const struct net *net, const struct nft_set *set, struct nft_rbtree_elem *new, struct nft_set_ext **ext) @@ -336,6 +408,7 @@ static struct nft_set_ops nft_rbtree_ops __read_mostly = { .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, }; |