diff options
Diffstat (limited to 'net/ipv4/netfilter/arp_tables.c')
-rw-r--r-- | net/ipv4/netfilter/arp_tables.c | 115 |
1 files changed, 88 insertions, 27 deletions
diff --git a/net/ipv4/netfilter/arp_tables.c b/net/ipv4/netfilter/arp_tables.c index b5db46342614..64a7c6ce0b98 100644 --- a/net/ipv4/netfilter/arp_tables.c +++ b/net/ipv4/netfilter/arp_tables.c @@ -261,9 +261,10 @@ unsigned int arpt_do_table(struct sk_buff *skb, indev = in ? in->name : nulldevname; outdev = out ? out->name : nulldevname; - read_lock_bh(&table->lock); - private = table->private; - table_base = (void *)private->entries[smp_processor_id()]; + rcu_read_lock(); + private = rcu_dereference(table->private); + table_base = rcu_dereference(private->entries[smp_processor_id()]); + e = get_entry(table_base, private->hook_entry[hook]); back = get_entry(table_base, private->underflow[hook]); @@ -335,7 +336,8 @@ unsigned int arpt_do_table(struct sk_buff *skb, e = (void *)e + e->next_offset; } } while (!hotdrop); - read_unlock_bh(&table->lock); + + rcu_read_unlock(); if (hotdrop) return NF_DROP; @@ -738,11 +740,65 @@ static void get_counters(const struct xt_table_info *t, } } -static inline struct xt_counters *alloc_counters(struct xt_table *table) + +/* We're lazy, and add to the first CPU; overflow works its fey magic + * and everything is OK. */ +static int +add_counter_to_entry(struct arpt_entry *e, + const struct xt_counters addme[], + unsigned int *i) +{ + ADD_COUNTER(e->counters, addme[*i].bcnt, addme[*i].pcnt); + + (*i)++; + return 0; +} + +/* Take values from counters and add them back onto the current cpu */ +static void put_counters(struct xt_table_info *t, + const struct xt_counters counters[]) +{ + unsigned int i, cpu; + + local_bh_disable(); + cpu = smp_processor_id(); + i = 0; + ARPT_ENTRY_ITERATE(t->entries[cpu], + t->size, + add_counter_to_entry, + counters, + &i); + local_bh_enable(); +} + +static inline int +zero_entry_counter(struct arpt_entry *e, void *arg) +{ + e->counters.bcnt = 0; + e->counters.pcnt = 0; + return 0; +} + +static void +clone_counters(struct xt_table_info *newinfo, const struct xt_table_info *info) +{ + unsigned int cpu; + const void *loc_cpu_entry = info->entries[raw_smp_processor_id()]; + + memcpy(newinfo, info, offsetof(struct xt_table_info, entries)); + for_each_possible_cpu(cpu) { + memcpy(newinfo->entries[cpu], loc_cpu_entry, info->size); + ARPT_ENTRY_ITERATE(newinfo->entries[cpu], newinfo->size, + zero_entry_counter, NULL); + } +} + +static struct xt_counters *alloc_counters(struct xt_table *table) { unsigned int countersize; struct xt_counters *counters; - const struct xt_table_info *private = table->private; + struct xt_table_info *private = table->private; + struct xt_table_info *info; /* We need atomic snapshot of counters: rest doesn't change * (other than comefrom, which userspace doesn't care @@ -752,14 +808,30 @@ static inline struct xt_counters *alloc_counters(struct xt_table *table) counters = vmalloc_node(countersize, numa_node_id()); if (counters == NULL) - return ERR_PTR(-ENOMEM); + goto nomem; + + info = xt_alloc_table_info(private->size); + if (!info) + goto free_counters; - /* First, sum counters... */ - write_lock_bh(&table->lock); - get_counters(private, counters); - write_unlock_bh(&table->lock); + clone_counters(info, private); + + mutex_lock(&table->lock); + xt_table_entry_swap_rcu(private, info); + synchronize_net(); /* Wait until smoke has cleared */ + + get_counters(info, counters); + put_counters(private, counters); + mutex_unlock(&table->lock); + + xt_free_table_info(info); return counters; + + free_counters: + vfree(counters); + nomem: + return ERR_PTR(-ENOMEM); } static int copy_entries_to_user(unsigned int total_size, @@ -1099,20 +1171,6 @@ static int do_replace(struct net *net, void __user *user, unsigned int len) return ret; } -/* We're lazy, and add to the first CPU; overflow works its fey magic - * and everything is OK. - */ -static inline int add_counter_to_entry(struct arpt_entry *e, - const struct xt_counters addme[], - unsigned int *i) -{ - - ADD_COUNTER(e->counters, addme[*i].bcnt, addme[*i].pcnt); - - (*i)++; - return 0; -} - static int do_add_counters(struct net *net, void __user *user, unsigned int len, int compat) { @@ -1172,13 +1230,14 @@ static int do_add_counters(struct net *net, void __user *user, unsigned int len, goto free; } - write_lock_bh(&t->lock); + mutex_lock(&t->lock); private = t->private; if (private->number != num_counters) { ret = -EINVAL; goto unlock_up_free; } + preempt_disable(); i = 0; /* Choose the copy that is on our node */ loc_cpu_entry = private->entries[smp_processor_id()]; @@ -1187,8 +1246,10 @@ static int do_add_counters(struct net *net, void __user *user, unsigned int len, add_counter_to_entry, paddc, &i); + preempt_enable(); unlock_up_free: - write_unlock_bh(&t->lock); + mutex_unlock(&t->lock); + xt_table_unlock(t); module_put(t->me); free: |