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author | David S. Miller <davem@davemloft.net> | 2016-07-24 22:02:36 -0700 |
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committer | David S. Miller <davem@davemloft.net> | 2016-07-24 22:02:36 -0700 |
commit | c42d7121fbee1ee30fd9221d594e9c5a4bc1fed6 (patch) | |
tree | 37ccf6ebfc28dc4aad92e9d3831d8825eafb7a5a /net/netfilter/nf_conntrack_core.c | |
parent | de0ba9a0d8909996f9e293d311c2cc459fa77d67 (diff) | |
parent | 4b512e1c1f8de6b9ceb796ecef8658e0a083cab7 (diff) |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next
Pablo Neira Ayuso says:
====================
Netfilter/IPVS updates for net-next
The following patchset contains Netfilter/IPVS updates for net-next,
they are:
1) Count pre-established connections as active in "least connection"
schedulers such that pre-established connections to avoid overloading
backend servers on peak demands, from Michal Kubecek via Simon Horman.
2) Address a race condition when resizing the conntrack table by caching
the bucket size when fulling iterating over the hashtable in these
three possible scenarios: 1) dump via /proc/net/nf_conntrack,
2) unlinking userspace helper and 3) unlinking custom conntrack timeout.
From Liping Zhang.
3) Revisit early_drop() path to perform lockless traversal on conntrack
eviction under stress, use del_timer() as synchronization point to
avoid two CPUs evicting the same entry, from Florian Westphal.
4) Move NAT hlist_head to nf_conn object, this simplifies the existing
NAT extension and it doesn't increase size since recent patches to
align nf_conn, from Florian.
5) Use rhashtable for the by-source NAT hashtable, also from Florian.
6) Don't allow --physdev-is-out from OUTPUT chain, just like
--physdev-out is not either, from Hangbin Liu.
7) Automagically set on nf_conntrack counters if the user tries to
match ct bytes/packets from nftables, from Liping Zhang.
8) Remove possible_net_t fields in nf_tables set objects since we just
simply pass the net pointer to the backend set type implementations.
9) Fix possible off-by-one in h323, from Toby DiPasquale.
10) early_drop() may be called from ctnetlink patch, so we must hold
rcu read size lock from them too, this amends Florian's patch #3
coming in this batch, from Liping Zhang.
11) Use binary search to validate jump offset in x_tables, this
addresses the O(n!) validation that was introduced recently
resolve security issues with unpriviledge namespaces, from Florian.
12) Fix reference leak to connlabel in error path of nft_ct, from Zhang.
13) Three updates for nft_log: Fix log prefix leak in error path. Bail
out on loglevel larger than debug in nft_log and set on the new
NF_LOG_F_COPY_LEN flag when snaplen is specified. Again from Zhang.
14) Allow to filter rule dumps in nf_tables based on table and chain
names.
15) Simplify connlabel to always use 128 bits to store labels and
get rid of unused function in xt_connlabel, from Florian.
16) Replace set_expect_timeout() by mod_timer() from the h323 conntrack
helper, by Gao Feng.
17) Put back x_tables module reference in nft_compat on error, from
Liping Zhang.
18) Add a reference count to the x_tables extensions cache in
nft_compat, so we can remove them when unused and avoid a crash
if the extensions are rmmod, again from Zhang.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/netfilter/nf_conntrack_core.c')
-rw-r--r-- | net/netfilter/nf_conntrack_core.c | 115 |
1 files changed, 67 insertions, 48 deletions
diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c index 0ad936814fa2..9198e690e692 100644 --- a/net/netfilter/nf_conntrack_core.c +++ b/net/netfilter/nf_conntrack_core.c @@ -460,6 +460,23 @@ nf_ct_key_equal(struct nf_conntrack_tuple_hash *h, net_eq(net, nf_ct_net(ct)); } +/* must be called with rcu read lock held */ +void nf_conntrack_get_ht(struct hlist_nulls_head **hash, unsigned int *hsize) +{ + struct hlist_nulls_head *hptr; + unsigned int sequence, hsz; + + do { + sequence = read_seqcount_begin(&nf_conntrack_generation); + hsz = nf_conntrack_htable_size; + hptr = nf_conntrack_hash; + } while (read_seqcount_retry(&nf_conntrack_generation, sequence)); + + *hash = hptr; + *hsize = hsz; +} +EXPORT_SYMBOL_GPL(nf_conntrack_get_ht); + /* * Warning : * - Caller must take a reference on returned object @@ -818,67 +835,69 @@ EXPORT_SYMBOL_GPL(nf_conntrack_tuple_taken); /* There's a small race here where we may free a just-assured connection. Too bad: we're in trouble anyway. */ -static noinline int early_drop(struct net *net, unsigned int _hash) +static unsigned int early_drop_list(struct net *net, + struct hlist_nulls_head *head) { - /* Use oldest entry, which is roughly LRU */ struct nf_conntrack_tuple_hash *h; - struct nf_conn *tmp; struct hlist_nulls_node *n; - unsigned int i, hash, sequence; - struct nf_conn *ct = NULL; - spinlock_t *lockp; - bool ret = false; + unsigned int drops = 0; + struct nf_conn *tmp; - i = 0; + hlist_nulls_for_each_entry_rcu(h, n, head, hnnode) { + tmp = nf_ct_tuplehash_to_ctrack(h); - local_bh_disable(); -restart: - sequence = read_seqcount_begin(&nf_conntrack_generation); - for (; i < NF_CT_EVICTION_RANGE; i++) { - hash = scale_hash(_hash++); - lockp = &nf_conntrack_locks[hash % CONNTRACK_LOCKS]; - nf_conntrack_lock(lockp); - if (read_seqcount_retry(&nf_conntrack_generation, sequence)) { - spin_unlock(lockp); - goto restart; - } - hlist_nulls_for_each_entry_rcu(h, n, &nf_conntrack_hash[hash], - hnnode) { - tmp = nf_ct_tuplehash_to_ctrack(h); - - if (test_bit(IPS_ASSURED_BIT, &tmp->status) || - !net_eq(nf_ct_net(tmp), net) || - nf_ct_is_dying(tmp)) - continue; - - if (atomic_inc_not_zero(&tmp->ct_general.use)) { - ct = tmp; - break; - } - } + if (test_bit(IPS_ASSURED_BIT, &tmp->status) || + !net_eq(nf_ct_net(tmp), net) || + nf_ct_is_dying(tmp)) + continue; - spin_unlock(lockp); - if (ct) - break; + if (!atomic_inc_not_zero(&tmp->ct_general.use)) + continue; + + /* kill only if still in same netns -- might have moved due to + * SLAB_DESTROY_BY_RCU rules. + * + * We steal the timer reference. If that fails timer has + * already fired or someone else deleted it. Just drop ref + * and move to next entry. + */ + if (net_eq(nf_ct_net(tmp), net) && + nf_ct_is_confirmed(tmp) && + del_timer(&tmp->timeout) && + nf_ct_delete(tmp, 0, 0)) + drops++; + + nf_ct_put(tmp); } - local_bh_enable(); + return drops; +} - if (!ct) - return false; +static noinline int early_drop(struct net *net, unsigned int _hash) +{ + unsigned int i; - /* kill only if in same netns -- might have moved due to - * SLAB_DESTROY_BY_RCU rules - */ - if (net_eq(nf_ct_net(ct), net) && del_timer(&ct->timeout)) { - if (nf_ct_delete(ct, 0, 0)) { - NF_CT_STAT_INC_ATOMIC(net, early_drop); - ret = true; + for (i = 0; i < NF_CT_EVICTION_RANGE; i++) { + struct hlist_nulls_head *ct_hash; + unsigned hash, sequence, drops; + + rcu_read_lock(); + do { + sequence = read_seqcount_begin(&nf_conntrack_generation); + hash = scale_hash(_hash++); + ct_hash = nf_conntrack_hash; + } while (read_seqcount_retry(&nf_conntrack_generation, sequence)); + + drops = early_drop_list(net, &ct_hash[hash]); + rcu_read_unlock(); + + if (drops) { + NF_CT_STAT_ADD_ATOMIC(net, early_drop, drops); + return true; } } - nf_ct_put(ct); - return ret; + return false; } static struct nf_conn * |