diff options
Diffstat (limited to 'net/netfilter/x_tables.c')
| -rw-r--r-- | net/netfilter/x_tables.c | 71 |
1 files changed, 55 insertions, 16 deletions
diff --git a/net/netfilter/x_tables.c b/net/netfilter/x_tables.c index d8571f414208..0b56bf05c169 100644 --- a/net/netfilter/x_tables.c +++ b/net/netfilter/x_tables.c @@ -1027,7 +1027,7 @@ void xt_free_table_info(struct xt_table_info *info) } EXPORT_SYMBOL(xt_free_table_info); -/* Find table by name, grabs mutex & ref. Returns NULL on error. */ +/* Find table by name, grabs mutex & ref. Returns ERR_PTR on error. */ struct xt_table *xt_find_table_lock(struct net *net, u_int8_t af, const char *name) { @@ -1043,17 +1043,17 @@ struct xt_table *xt_find_table_lock(struct net *net, u_int8_t af, /* Table doesn't exist in this netns, re-try init */ list_for_each_entry(t, &init_net.xt.tables[af], list) { + int err; + if (strcmp(t->name, name)) continue; - if (!try_module_get(t->me)) { - mutex_unlock(&xt[af].mutex); - return NULL; - } - + if (!try_module_get(t->me)) + goto out; mutex_unlock(&xt[af].mutex); - if (t->table_init(net) != 0) { + err = t->table_init(net); + if (err < 0) { module_put(t->me); - return NULL; + return ERR_PTR(err); } found = t; @@ -1073,10 +1073,28 @@ struct xt_table *xt_find_table_lock(struct net *net, u_int8_t af, module_put(found->me); out: mutex_unlock(&xt[af].mutex); - return NULL; + return ERR_PTR(-ENOENT); } EXPORT_SYMBOL_GPL(xt_find_table_lock); +struct xt_table *xt_request_find_table_lock(struct net *net, u_int8_t af, + const char *name) +{ + struct xt_table *t = xt_find_table_lock(net, af, name); + +#ifdef CONFIG_MODULES + if (IS_ERR(t)) { + int err = request_module("%stable_%s", xt_prefix[af], name); + if (err < 0) + return ERR_PTR(err); + t = xt_find_table_lock(net, af, name); + } +#endif + + return t; +} +EXPORT_SYMBOL_GPL(xt_request_find_table_lock); + void xt_table_unlock(struct xt_table *table) { mutex_unlock(&xt[table->af].mutex); @@ -1153,6 +1171,7 @@ xt_replace_table(struct xt_table *table, int *error) { struct xt_table_info *private; + unsigned int cpu; int ret; ret = xt_jumpstack_alloc(newinfo); @@ -1182,14 +1201,28 @@ xt_replace_table(struct xt_table *table, smp_wmb(); table->private = newinfo; + /* make sure all cpus see new ->private value */ + smp_wmb(); + /* * Even though table entries have now been swapped, other CPU's - * may still be using the old entries. This is okay, because - * resynchronization happens because of the locking done - * during the get_counters() routine. + * may still be using the old entries... */ local_bh_enable(); + /* ... so wait for even xt_recseq on all cpus */ + for_each_possible_cpu(cpu) { + seqcount_t *s = &per_cpu(xt_recseq, cpu); + u32 seq = raw_read_seqcount(s); + + if (seq & 1) { + do { + cond_resched(); + cpu_relax(); + } while (seq == raw_read_seqcount(s)); + } + } + #ifdef CONFIG_AUDIT if (audit_enabled) { audit_log(current->audit_context, GFP_KERNEL, @@ -1329,7 +1362,6 @@ static int xt_table_open(struct inode *inode, struct file *file) } static const struct file_operations xt_table_ops = { - .owner = THIS_MODULE, .open = xt_table_open, .read = seq_read, .llseek = seq_lseek, @@ -1382,7 +1414,7 @@ static void *xt_mttg_seq_next(struct seq_file *seq, void *v, loff_t *ppos, trav->curr = trav->curr->next; if (trav->curr != trav->head) break; - /* fallthru, _stop will unlock */ + /* fall through */ default: return NULL; } @@ -1465,7 +1497,6 @@ static int xt_match_open(struct inode *inode, struct file *file) } static const struct file_operations xt_match_ops = { - .owner = THIS_MODULE, .open = xt_match_open, .read = seq_read, .llseek = seq_lseek, @@ -1518,7 +1549,6 @@ static int xt_target_open(struct inode *inode, struct file *file) } static const struct file_operations xt_target_ops = { - .owner = THIS_MODULE, .open = xt_target_open, .read = seq_read, .llseek = seq_lseek, @@ -1714,8 +1744,17 @@ static int __net_init xt_net_init(struct net *net) return 0; } +static void __net_exit xt_net_exit(struct net *net) +{ + int i; + + for (i = 0; i < NFPROTO_NUMPROTO; i++) + WARN_ON_ONCE(!list_empty(&net->xt.tables[i])); +} + static struct pernet_operations xt_net_ops = { .init = xt_net_init, + .exit = xt_net_exit, }; static int __init xt_init(void) |