From f28e15bacedd444608e25421c72eb2cf4527c9ca Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Tue, 22 Nov 2016 14:44:18 +0100 Subject: [PATCH] netfilter: x_tables: pass xt_counters struct to counter allocator Keeps some noise away from a followup patch. Signed-off-by: Florian Westphal Acked-by: Eric Dumazet Signed-off-by: Pablo Neira Ayuso --- include/linux/netfilter/x_tables.h | 27 +-------------------------- net/ipv4/netfilter/arp_tables.c | 5 +---- net/ipv4/netfilter/ip_tables.c | 5 +---- net/ipv6/netfilter/ip6_tables.c | 5 +---- net/netfilter/x_tables.c | 30 ++++++++++++++++++++++++++++++ 5 files changed, 34 insertions(+), 38 deletions(-) diff --git a/include/linux/netfilter/x_tables.h b/include/linux/netfilter/x_tables.h index 6e61edeb68e3..05a94bd32c55 100644 --- a/include/linux/netfilter/x_tables.h +++ b/include/linux/netfilter/x_tables.h @@ -404,32 +404,7 @@ 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 019f8e8dda6d..808deb275ceb 100644 --- a/net/ipv4/netfilter/arp_tables.c +++ b/net/ipv4/netfilter/arp_tables.c @@ -415,13 +415,10 @@ 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 acc9a0c45bdf..a48430d3420f 100644 --- a/net/ipv4/netfilter/ip_tables.c +++ b/net/ipv4/netfilter/ip_tables.c @@ -539,12 +539,9 @@ 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 88b56a98905b..a5a92083fd62 100644 --- a/net/ipv6/netfilter/ip6_tables.c +++ b/net/ipv6/netfilter/ip6_tables.c @@ -570,12 +570,9 @@ 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 0580029eb0ee..be5e83047594 100644 --- a/net/netfilter/x_tables.c +++ b/net/netfilter/x_tables.c @@ -1615,6 +1615,36 @@ 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; -- 2.20.1