diff options
| author | Patrick McHardy | 2015-04-05 14:41:06 +0200 |
|---|---|---|
| committer | Pablo Neira Ayuso | 2015-04-08 16:58:27 +0200 |
| commit | 3dd0673ac3cd7d05cde103396ec7ec410a901de2 (patch) | |
| tree | 4daf53c5aef7eade635652cd37c023fbd4e75bc1 /net/netfilter/nf_tables_api.c | |
| parent | netfilter: nf_tables: fix set selection when timeouts are requested (diff) | |
| download | kernel-qcow2-linux-3dd0673ac3cd7d05cde103396ec7ec410a901de2.tar.gz kernel-qcow2-linux-3dd0673ac3cd7d05cde103396ec7ec410a901de2.tar.xz kernel-qcow2-linux-3dd0673ac3cd7d05cde103396ec7ec410a901de2.zip | |
netfilter: nf_tables: prepare set element accounting for async updates
Use atomic operations for the element count to avoid races with async
updates.
To properly handle the transactional semantics during netlink updates,
deleted but not yet committed elements are accounted for seperately and
are treated as being already removed. This means for the duration of
a netlink transaction, the limit might be exceeded by the amount of
elements deleted. Set implementations must be prepared to handle this.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'net/netfilter/nf_tables_api.c')
| -rw-r--r-- | net/netfilter/nf_tables_api.c | 21 |
1 files changed, 12 insertions, 9 deletions
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 0dab872e821b..27d1bf55a581 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -3238,9 +3238,6 @@ static int nft_add_set_elem(struct nft_ctx *ctx, struct nft_set *set, u32 flags; int err; - if (set->size && set->nelems == set->size) - return -ENFILE; - err = nla_parse_nested(nla, NFTA_SET_ELEM_MAX, attr, nft_set_elem_policy); if (err < 0) @@ -3391,11 +3388,15 @@ static int nf_tables_newsetelem(struct sock *nlsk, struct sk_buff *skb, return -EBUSY; nla_for_each_nested(attr, nla[NFTA_SET_ELEM_LIST_ELEMENTS], rem) { + if (set->size && + !atomic_add_unless(&set->nelems, 1, set->size + set->ndeact)) + return -ENFILE; + err = nft_add_set_elem(&ctx, set, attr); - if (err < 0) + if (err < 0) { + atomic_dec(&set->nelems); break; - - set->nelems++; + } } return err; } @@ -3477,7 +3478,7 @@ static int nf_tables_delsetelem(struct sock *nlsk, struct sk_buff *skb, if (err < 0) break; - set->nelems--; + set->ndeact++; } return err; } @@ -3810,6 +3811,8 @@ static int nf_tables_commit(struct sk_buff *skb) &te->elem, NFT_MSG_DELSETELEM, 0); te->set->ops->remove(te->set, &te->elem); + atomic_dec(&te->set->nelems); + te->set->ndeact--; break; } } @@ -3913,16 +3916,16 @@ static int nf_tables_abort(struct sk_buff *skb) nft_trans_destroy(trans); break; case NFT_MSG_NEWSETELEM: - nft_trans_elem_set(trans)->nelems--; te = (struct nft_trans_elem *)trans->data; te->set->ops->remove(te->set, &te->elem); + atomic_dec(&te->set->nelems); break; case NFT_MSG_DELSETELEM: te = (struct nft_trans_elem *)trans->data; - nft_trans_elem_set(trans)->nelems++; te->set->ops->activate(te->set, &te->elem); + te->set->ndeact--; nft_trans_destroy(trans); break; |