netfilter: x_tables: pass xt_counters struct to counter allocator

commit f28e15bacedd444608e25421c72eb2cf4527c9ca upstream.

Keeps some noise away from a followup patch.

Signed-off-by: Florian Westphal <fw@strlen.de>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/include/linux/netfilter/x_tables.h b/include/linux/netfilter/x_tables.h
index 5950b5a..1c9b228 100644 (file)
--- a/include/linux/netfilter/x_tables.h
+++ b/include/linux/netfilter/x_tables.h
@@ -369,32 +369,7 @@ static inline unsigned long ifname_compare_aligned(const char *_a,
 }
 
 
-/* On SMP, ip(6)t_entry->counters.pcnt holds address of the
- * real (percpu) counter.  On !SMP, its just the packet count,
- * so nothing needs to be done there.
- *
- * xt_percpu_counter_alloc returns the address of the percpu
- * counter, or 0 on !SMP. We force an alignment of 16 bytes
- * so that bytes/packets share a common cache line.
- *
- * Hence caller must use IS_ERR_VALUE to check for error, this
- * allows us to return 0 for single core systems without forcing
- * callers to deal with SMP vs. NONSMP issues.
- */
-static inline unsigned long xt_percpu_counter_alloc(void)
-{
-       if (nr_cpu_ids > 1) {
-               void __percpu *res = __alloc_percpu(sizeof(struct xt_counters),
-                                                   sizeof(struct xt_counters));
-
-               if (res == NULL)
-                       return -ENOMEM;
-
-               return (__force unsigned long) res;
-       }
-
-       return 0;
-}
+bool xt_percpu_counter_alloc(struct xt_counters *counters);
 void xt_percpu_counter_free(struct xt_counters *cnt);
 
 static inline struct xt_counters *

diff --git a/net/ipv4/netfilter/arp_tables.c b/net/ipv4/netfilter/arp_tables.c
index e689deb..e4ac858 100644 (file)
--- a/net/ipv4/netfilter/arp_tables.c
+++ b/net/ipv4/netfilter/arp_tables.c
@@ -515,13 +515,10 @@ find_check_entry(struct arpt_entry *e, const char *name, unsigned int size)
 {
        struct xt_entry_target *t;
        struct xt_target *target;
-       unsigned long pcnt;
        int ret;
 
-       pcnt = xt_percpu_counter_alloc();
-       if (IS_ERR_VALUE(pcnt))
+       if (!xt_percpu_counter_alloc(&e->counters))
                return -ENOMEM;
-       e->counters.pcnt = pcnt;
 
        t = arpt_get_target(e);
        target = xt_request_find_target(NFPROTO_ARP, t->u.user.name,

diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c
index 2d83604..be7405a 100644 (file)
--- a/net/ipv4/netfilter/ip_tables.c
+++ b/net/ipv4/netfilter/ip_tables.c
@@ -657,12 +657,9 @@ find_check_entry(struct ipt_entry *e, struct net *net, const char *name,
        unsigned int j;
        struct xt_mtchk_param mtpar;
        struct xt_entry_match *ematch;
-       unsigned long pcnt;
 
-       pcnt = xt_percpu_counter_alloc();
-       if (IS_ERR_VALUE(pcnt))
+       if (!xt_percpu_counter_alloc(&e->counters))
                return -ENOMEM;
-       e->counters.pcnt = pcnt;
 
        j = 0;
        mtpar.net       = net;

diff --git a/net/ipv6/netfilter/ip6_tables.c b/net/ipv6/netfilter/ip6_tables.c
index 274adec..a4f39f7 100644 (file)
--- a/net/ipv6/netfilter/ip6_tables.c
+++ b/net/ipv6/netfilter/ip6_tables.c
@@ -670,12 +670,9 @@ find_check_entry(struct ip6t_entry *e, struct net *net, const char *name,
        unsigned int j;
        struct xt_mtchk_param mtpar;
        struct xt_entry_match *ematch;
-       unsigned long pcnt;
 
-       pcnt = xt_percpu_counter_alloc();
-       if (IS_ERR_VALUE(pcnt))
+       if (!xt_percpu_counter_alloc(&e->counters))
                return -ENOMEM;
-       e->counters.pcnt = pcnt;
 
        j = 0;
        mtpar.net       = net;

diff --git a/net/netfilter/x_tables.c b/net/netfilter/x_tables.c
index a847122..cfab40c 100644 (file)
--- a/net/netfilter/x_tables.c
+++ b/net/netfilter/x_tables.c
@@ -1592,6 +1592,36 @@ void xt_proto_fini(struct net *net, u_int8_t af)
 }
 EXPORT_SYMBOL_GPL(xt_proto_fini);
 
+/**
+ * xt_percpu_counter_alloc - allocate x_tables rule counter
+ *
+ * @counter: pointer to counter struct inside the ip(6)/arpt_entry struct
+ *
+ * On SMP, the packet counter [ ip(6)t_entry->counters.pcnt ] will then
+ * contain the address of the real (percpu) counter.
+ *
+ * Rule evaluation needs to use xt_get_this_cpu_counter() helper
+ * to fetch the real percpu counter.
+ *
+ * returns false on error.
+ */
+bool xt_percpu_counter_alloc(struct xt_counters *counter)
+{
+       void __percpu *res;
+
+       if (nr_cpu_ids <= 1)
+               return true;
+
+       res = __alloc_percpu(sizeof(struct xt_counters),
+                            sizeof(struct xt_counters));
+       if (!res)
+               return false;
+
+       counter->pcnt = (__force unsigned long)res;
+       return true;
+}
+EXPORT_SYMBOL_GPL(xt_percpu_counter_alloc);
+
 void xt_percpu_counter_free(struct xt_counters *counters)
 {
        unsigned long pcnt = counters->pcnt;