[NETFILTER]: Use only 32bit counters for CONNTRACK_ACCT

Initially we used 64bit counters for conntrack-based accounting, since we
had no event mechanism to tell userspace that our counters are about to
overflow.  With nfnetlink_conntrack, we now have such a event mechanism and
thus can save 16bytes per connection.

Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

4 files changed, 22 insertions, 13 deletions

diff --git a/include/linux/netfilter/nfnetlink_conntrack.h b/include/linux/netfilter/nfnetlink_conntrack.h
index fb5511030185..116fcaced909 100644
--- a/include/linux/netfilter/nfnetlink_conntrack.h
+++ b/include/linux/netfilter/nfnetlink_conntrack.h
@@ -84,8 +84,10 @@ enum ctattr_protoinfo_tcp {
 
 enum ctattr_counters {
         CTA_COUNTERS_UNSPEC,
-        CTA_COUNTERS_PACKETS,
-        CTA_COUNTERS_BYTES,
+        CTA_COUNTERS_PACKETS,           /* old 64bit counters */
+        CTA_COUNTERS_BYTES,             /* old 64bit counters */
+        CTA_COUNTERS32_PACKETS,
+        CTA_COUNTERS32_BYTES,
         __CTA_COUNTERS_MAX
 };
 #define CTA_COUNTERS_MAX (__CTA_COUNTERS_MAX - 1)
diff --git a/include/linux/netfilter_ipv4/ip_conntrack.h b/include/linux/netfilter_ipv4/ip_conntrack.h
index 4ced38736813..d078bb91d9e5 100644
--- a/include/linux/netfilter_ipv4/ip_conntrack.h
+++ b/include/linux/netfilter_ipv4/ip_conntrack.h
@@ -117,6 +117,10 @@ enum ip_conntrack_events
         /* NAT info */
         IPCT_NATINFO_BIT = 10,
         IPCT_NATINFO = (1 << IPCT_NATINFO_BIT),
+
+        /* Counter highest bit has been set */
+        IPCT_COUNTER_FILLING_BIT = 11,
+        IPCT_COUNTER_FILLING = (1 << IPCT_COUNTER_FILLING_BIT),
 };
 
 enum ip_conntrack_expect_events {
@@ -192,8 +196,8 @@ do {									\
 
 struct ip_conntrack_counter
 {
-        u_int64_t packets;
-        u_int64_t bytes;
+        u_int32_t packets;
+        u_int32_t bytes;
 };
 
 struct ip_conntrack_helper;
diff --git a/net/ipv4/netfilter/ip_conntrack_core.c b/net/ipv4/netfilter/ip_conntrack_core.c
index ea65dd3e517a..07a80b56e8dc 100644
--- a/net/ipv4/netfilter/ip_conntrack_core.c
+++ b/net/ipv4/netfilter/ip_conntrack_core.c
@@ -1119,7 +1119,7 @@ void __ip_ct_refresh_acct(struct ip_conntrack *ct,
                         unsigned long extra_jiffies,
                         int do_acct)
 {
-        int do_event = 0;
+        int event = 0;
 
         IP_NF_ASSERT(ct->timeout.data == (unsigned long)ct);
         IP_NF_ASSERT(skb);
@@ -1129,13 +1129,13 @@ void __ip_ct_refresh_acct(struct ip_conntrack *ct,
         /* If not in hash table, timer will not be active yet */
         if (!is_confirmed(ct)) {
                 ct->timeout.expires = extra_jiffies;
-                do_event = 1;
+                event = IPCT_REFRESH;
         } else {
                 /* Need del_timer for race avoidance (may already be dying). */
                 if (del_timer(&ct->timeout)) {
                         ct->timeout.expires = jiffies + extra_jiffies;
                         add_timer(&ct->timeout);
-                        do_event = 1;
+                        event = IPCT_REFRESH;
                 }
         }
 
@@ -1144,14 +1144,17 @@ void __ip_ct_refresh_acct(struct ip_conntrack *ct,
                 ct->counters[CTINFO2DIR(ctinfo)].packets++;
                 ct->counters[CTINFO2DIR(ctinfo)].bytes += 
                                                 ntohs(skb->nh.iph->tot_len);
+                if ((ct->counters[CTINFO2DIR(ctinfo)].packets & 0x80000000)
+                    || (ct->counters[CTINFO2DIR(ctinfo)].bytes & 0x80000000))
+                        event |= IPCT_COUNTER_FILLING;
         }
 #endif
 
         write_unlock_bh(&ip_conntrack_lock);
 
         /* must be unlocked when calling event cache */
-        if (do_event)
-                ip_conntrack_event_cache(IPCT_REFRESH, skb);
+        if (event)
+                ip_conntrack_event_cache(event, skb);
 }
 
 #if defined(CONFIG_IP_NF_CONNTRACK_NETLINK) || \
diff --git a/net/ipv4/netfilter/ip_conntrack_netlink.c b/net/ipv4/netfilter/ip_conntrack_netlink.c
index eade2749915a..06ed91ee8ace 100644
--- a/net/ipv4/netfilter/ip_conntrack_netlink.c
+++ b/net/ipv4/netfilter/ip_conntrack_netlink.c
@@ -177,11 +177,11 @@ ctnetlink_dump_counters(struct sk_buff *skb, const struct ip_conntrack *ct,
         struct nfattr *nest_count = NFA_NEST(skb, type);
         u_int64_t tmp;
 
-        tmp = cpu_to_be64(ct->counters[dir].packets);
-        NFA_PUT(skb, CTA_COUNTERS_PACKETS, sizeof(u_int64_t), &tmp);
+        tmp = htonl(ct->counters[dir].packets);
+        NFA_PUT(skb, CTA_COUNTERS32_PACKETS, sizeof(u_int32_t), &tmp);
 
-        tmp = cpu_to_be64(ct->counters[dir].bytes);
-        NFA_PUT(skb, CTA_COUNTERS_BYTES, sizeof(u_int64_t), &tmp);
+        tmp = htonl(ct->counters[dir].bytes);
+        NFA_PUT(skb, CTA_COUNTERS32_BYTES, sizeof(u_int32_t), &tmp);
 
         NFA_NEST_END(skb, nest_count);