diff options
author | Krishna Kumar <krkumar2@in.ibm.com> | 2012-05-24 03:56:44 (GMT) |
---|---|---|
committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2012-06-07 12:58:39 (GMT) |
commit | fdb694a01f1fcd30fd16d8aa290c34699fe98a17 (patch) | |
tree | 4da135c27f582e3a3f6891a4bc4bf4abb6a57829 /net/netfilter | |
parent | 68c07cb6d8aa05daf38ab47d5bb674d81a2066fb (diff) | |
download | linux-fdb694a01f1fcd30fd16d8aa290c34699fe98a17.tar.xz |
netfilter: Add fail-open support
Implement a new "fail-open" mode where packets are not dropped
upon queue-full condition. This mode can be enabled/disabled per
queue using netlink NFQA_CFG_FLAGS & NFQA_CFG_MASK attributes.
Signed-off-by: Krishna Kumar <krkumar2@in.ibm.com>
Signed-off-by: Vivek Kashyap <vivk@us.ibm.com>
Signed-off-by: Sridhar Samudrala <samudrala@us.ibm.com>
Diffstat (limited to 'net/netfilter')
-rw-r--r-- | net/netfilter/nfnetlink_queue.c | 40 |
1 files changed, 37 insertions, 3 deletions
diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c index 4162437..630da3d 100644 --- a/net/netfilter/nfnetlink_queue.c +++ b/net/netfilter/nfnetlink_queue.c @@ -52,6 +52,7 @@ struct nfqnl_instance { u_int16_t queue_num; /* number of this queue */ u_int8_t copy_mode; + u_int32_t flags; /* Set using NFQA_CFG_FLAGS */ /* * Following fields are dirtied for each queued packet, * keep them in same cache line if possible. @@ -406,6 +407,7 @@ nfqnl_enqueue_packet(struct nf_queue_entry *entry, unsigned int queuenum) struct nfqnl_instance *queue; int err = -ENOBUFS; __be32 *packet_id_ptr; + int failopen = 0; /* rcu_read_lock()ed by nf_hook_slow() */ queue = instance_lookup(queuenum); @@ -431,9 +433,14 @@ nfqnl_enqueue_packet(struct nf_queue_entry *entry, unsigned int queuenum) goto err_out_free_nskb; } if (queue->queue_total >= queue->queue_maxlen) { - queue->queue_dropped++; - net_warn_ratelimited("nf_queue: full at %d entries, dropping packets(s)\n", - queue->queue_total); + if (queue->flags & NFQA_CFG_F_FAIL_OPEN) { + failopen = 1; + err = 0; + } else { + queue->queue_dropped++; + net_warn_ratelimited("nf_queue: full at %d entries, dropping packets(s)\n", + queue->queue_total); + } goto err_out_free_nskb; } entry->id = ++queue->id_sequence; @@ -455,6 +462,8 @@ err_out_free_nskb: kfree_skb(nskb); err_out_unlock: spin_unlock_bh(&queue->lock); + if (failopen) + nf_reinject(entry, NF_ACCEPT); err_out: return err; } @@ -858,6 +867,31 @@ nfqnl_recv_config(struct sock *ctnl, struct sk_buff *skb, spin_unlock_bh(&queue->lock); } + if (nfqa[NFQA_CFG_FLAGS]) { + __u32 flags, mask; + + if (!queue) { + ret = -ENODEV; + goto err_out_unlock; + } + + if (!nfqa[NFQA_CFG_MASK]) { + /* A mask is needed to specify which flags are being + * changed. + */ + ret = -EINVAL; + goto err_out_unlock; + } + + flags = ntohl(nla_get_be32(nfqa[NFQA_CFG_FLAGS])); + mask = ntohl(nla_get_be32(nfqa[NFQA_CFG_MASK])); + + spin_lock_bh(&queue->lock); + queue->flags &= ~mask; + queue->flags |= flags & mask; + spin_unlock_bh(&queue->lock); + } + err_out_unlock: rcu_read_unlock(); return ret; |