netfilter: nf_nat: use per-conntrack locking for sequence number adjustments
Get rid of the global lock and use per-conntrack locks for protecting the
sequencen number adjustment data. Additionally saves one lock/unlock
operation for every TCP packet.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
diff --git a/net/netfilter/nf_nat_helper.c b/net/netfilter/nf_nat_helper.c
index ff4a589..46b9baa 100644
--- a/net/netfilter/nf_nat_helper.c
+++ b/net/netfilter/nf_nat_helper.c
@@ -30,8 +30,6 @@
pr_debug("offset_before=%d, offset_after=%d, correction_pos=%u\n", \
x->offset_before, x->offset_after, x->correction_pos);
-static DEFINE_SPINLOCK(nf_nat_seqofs_lock);
-
/* Setup TCP sequence correction given this change at this sequence */
static inline void
adjust_tcp_sequence(u32 seq,
@@ -49,7 +47,7 @@
pr_debug("adjust_tcp_sequence: Seq_offset before: ");
DUMP_OFFSET(this_way);
- spin_lock_bh(&nf_nat_seqofs_lock);
+ spin_lock_bh(&ct->lock);
/* SYN adjust. If it's uninitialized, or this is after last
* correction, record it: we don't handle more than one
@@ -61,31 +59,26 @@
this_way->offset_before = this_way->offset_after;
this_way->offset_after += sizediff;
}
- spin_unlock_bh(&nf_nat_seqofs_lock);
+ spin_unlock_bh(&ct->lock);
pr_debug("adjust_tcp_sequence: Seq_offset after: ");
DUMP_OFFSET(this_way);
}
-/* Get the offset value, for conntrack */
+/* Get the offset value, for conntrack. Caller must have the conntrack locked */
s32 nf_nat_get_offset(const struct nf_conn *ct,
enum ip_conntrack_dir dir,
u32 seq)
{
struct nf_conn_nat *nat = nfct_nat(ct);
struct nf_nat_seq *this_way;
- s32 offset;
if (!nat)
return 0;
this_way = &nat->seq[dir];
- spin_lock_bh(&nf_nat_seqofs_lock);
- offset = after(seq, this_way->correction_pos)
+ return after(seq, this_way->correction_pos)
? this_way->offset_after : this_way->offset_before;
- spin_unlock_bh(&nf_nat_seqofs_lock);
-
- return offset;
}
/* Frobs data inside this packet, which is linear. */
@@ -384,7 +377,7 @@
return 0;
tcph = (void *)skb->data + protoff;
- spin_lock_bh(&nf_nat_seqofs_lock);
+ spin_lock_bh(&ct->lock);
if (after(ntohl(tcph->seq), this_way->correction_pos))
seqoff = this_way->offset_after;
else
@@ -410,7 +403,7 @@
tcph->ack_seq = newack;
res = nf_nat_sack_adjust(skb, protoff, tcph, ct, ctinfo);
- spin_unlock_bh(&nf_nat_seqofs_lock);
+ spin_unlock_bh(&ct->lock);
return res;
}