netfilter: accounting rework: ct_extend + 64bit counters (v4)

Initially netfilter has had 64bit counters for conntrack-based accounting, but
it was changed in 2.6.14 to save memory. Unfortunately in-kernel 64bit counters are
still required, for example for "connbytes" extension. However, 64bit counters
waste a lot of memory and it was not possible to enable/disable it runtime.

This patch:
 - reimplements accounting with respect to the extension infrastructure,
 - makes one global version of seq_print_acct() instead of two seq_print_counters(),
 - makes it possible to enable it at boot time (for CONFIG_SYSCTL/CONFIG_SYSFS=n),
 - makes it possible to enable/disable it at runtime by sysctl or sysfs,
 - extends counters from 32bit to 64bit,
 - renames ip_conntrack_counter -> nf_conn_counter,
 - enables accounting code unconditionally (no longer depends on CONFIG_NF_CT_ACCT),
 - set initial accounting enable state based on CONFIG_NF_CT_ACCT
 - removes buggy IPCT_COUNTER_FILLING event handling.

If accounting is enabled newly created connections get additional acct extend.
Old connections are not changed as it is not possible to add a ct_extend area
to confirmed conntrack. Accounting is performed for all connections with
acct extend regardless of a current state of "net.netfilter.nf_conntrack_acct".

Signed-off-by: Krzysztof Piotr Oledzki <ole@ans.pl>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 26 insertions, 13 deletions

diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c
index 28d03e64200b..c519d090bdb9 100644
--- a/net/netfilter/nf_conntrack_core.c
+++ b/net/netfilter/nf_conntrack_core.c
@@ -37,6 +37,7 @@
 #include <net/netfilter/nf_conntrack_helper.h>
 #include <net/netfilter/nf_conntrack_core.h>
 #include <net/netfilter/nf_conntrack_extend.h>
+#include <net/netfilter/nf_conntrack_acct.h>
 
 #define NF_CONNTRACK_VERSION	"0.5.0"
 
@@ -555,6 +556,8 @@ init_conntrack(const struct nf_conntrack_tuple *tuple,
 		return NULL;
 	}
 
+	nf_ct_acct_ext_add(ct, GFP_ATOMIC);
+
 	spin_lock_bh(&nf_conntrack_lock);
 	exp = nf_ct_find_expectation(tuple);
 	if (exp) {
@@ -828,17 +831,16 @@ void __nf_ct_refresh_acct(struct nf_conn *ct,
 	}
 
 acct:
-#ifdef CONFIG_NF_CT_ACCT
 	if (do_acct) {
-		ct->counters[CTINFO2DIR(ctinfo)].packets++;
-		ct->counters[CTINFO2DIR(ctinfo)].bytes +=
-			skb->len - skb_network_offset(skb);
+		struct nf_conn_counter *acct;
 
-		if ((ct->counters[CTINFO2DIR(ctinfo)].packets & 0x80000000)
-		    || (ct->counters[CTINFO2DIR(ctinfo)].bytes & 0x80000000))
-			event |= IPCT_COUNTER_FILLING;
+		acct = nf_conn_acct_find(ct);
+		if (acct) {
+			acct[CTINFO2DIR(ctinfo)].packets++;
+			acct[CTINFO2DIR(ctinfo)].bytes +=
+				skb->len - skb_network_offset(skb);
+		}
 	}
-#endif
 
 	spin_unlock_bh(&nf_conntrack_lock);
 
@@ -853,15 +855,19 @@ bool __nf_ct_kill_acct(struct nf_conn *ct,
 		       const struct sk_buff *skb,
 		       int do_acct)
 {
-#ifdef CONFIG_NF_CT_ACCT
 	if (do_acct) {
+		struct nf_conn_counter *acct;
+
 		spin_lock_bh(&nf_conntrack_lock);
-		ct->counters[CTINFO2DIR(ctinfo)].packets++;
-		ct->counters[CTINFO2DIR(ctinfo)].bytes +=
-			skb->len - skb_network_offset(skb);
+		acct = nf_conn_acct_find(ct);
+		if (acct) {
+			acct[CTINFO2DIR(ctinfo)].packets++;
+			acct[CTINFO2DIR(ctinfo)].bytes +=
+				skb->len - skb_network_offset(skb);
+		}
 		spin_unlock_bh(&nf_conntrack_lock);
 	}
-#endif
+
 	if (del_timer(&ct->timeout)) {
 		ct->timeout.function((unsigned long)ct);
 		return true;
@@ -1029,6 +1035,7 @@ void nf_conntrack_cleanup(void)
 	nf_conntrack_proto_fini();
 	nf_conntrack_helper_fini();
 	nf_conntrack_expect_fini();
+	nf_conntrack_acct_fini();
 }
 
 struct hlist_head *nf_ct_alloc_hashtable(unsigned int *sizep, int *vmalloced)
@@ -1168,6 +1175,10 @@ int __init nf_conntrack_init(void)
 	if (ret < 0)
 		goto out_fini_expect;
 
+	ret = nf_conntrack_acct_init();
+	if (ret < 0)
+		goto out_fini_helper;
+
 	/* For use by REJECT target */
 	rcu_assign_pointer(ip_ct_attach, nf_conntrack_attach);
 	rcu_assign_pointer(nf_ct_destroy, destroy_conntrack);
@@ -1180,6 +1191,8 @@ int __init nf_conntrack_init(void)
 
 	return ret;
 
+out_fini_helper:
+	nf_conntrack_helper_fini();
 out_fini_expect:
 	nf_conntrack_expect_fini();
 out_fini_proto: