diff options
Diffstat (limited to 'net/netfilter/nf_conntrack_helper.c')
-rw-r--r-- | net/netfilter/nf_conntrack_helper.c | 86 |
1 files changed, 86 insertions, 0 deletions
diff --git a/net/netfilter/nf_conntrack_helper.c b/net/netfilter/nf_conntrack_helper.c index 274baf1dab87..918df7f71c8f 100644 --- a/net/netfilter/nf_conntrack_helper.c +++ b/net/netfilter/nf_conntrack_helper.c @@ -42,6 +42,9 @@ module_param_named(nf_conntrack_helper, nf_ct_auto_assign_helper, bool, 0644); MODULE_PARM_DESC(nf_conntrack_helper, "Enable automatic conntrack helper assignment (default 0)"); +static DEFINE_MUTEX(nf_ct_nat_helpers_mutex); +static struct list_head nf_ct_nat_helpers __read_mostly; + /* Stupid hash, but collision free for the default registrations of the * helpers currently in the kernel. */ static unsigned int helper_hash(const struct nf_conntrack_tuple *tuple) @@ -130,6 +133,70 @@ void nf_conntrack_helper_put(struct nf_conntrack_helper *helper) } EXPORT_SYMBOL_GPL(nf_conntrack_helper_put); +static struct nf_conntrack_nat_helper * +nf_conntrack_nat_helper_find(const char *mod_name) +{ + struct nf_conntrack_nat_helper *cur; + bool found = false; + + list_for_each_entry_rcu(cur, &nf_ct_nat_helpers, list) { + if (!strcmp(cur->mod_name, mod_name)) { + found = true; + break; + } + } + return found ? cur : NULL; +} + +int +nf_nat_helper_try_module_get(const char *name, u16 l3num, u8 protonum) +{ + struct nf_conntrack_helper *h; + struct nf_conntrack_nat_helper *nat; + char mod_name[NF_CT_HELPER_NAME_LEN]; + int ret = 0; + + rcu_read_lock(); + h = __nf_conntrack_helper_find(name, l3num, protonum); + if (!h) { + rcu_read_unlock(); + return -ENOENT; + } + + nat = nf_conntrack_nat_helper_find(h->nat_mod_name); + if (!nat) { + snprintf(mod_name, sizeof(mod_name), "%s", h->nat_mod_name); + rcu_read_unlock(); + request_module(mod_name); + + rcu_read_lock(); + nat = nf_conntrack_nat_helper_find(mod_name); + if (!nat) { + rcu_read_unlock(); + return -ENOENT; + } + } + + if (!try_module_get(nat->module)) + ret = -ENOENT; + + rcu_read_unlock(); + return ret; +} +EXPORT_SYMBOL_GPL(nf_nat_helper_try_module_get); + +void nf_nat_helper_put(struct nf_conntrack_helper *helper) +{ + struct nf_conntrack_nat_helper *nat; + + nat = nf_conntrack_nat_helper_find(helper->nat_mod_name); + if (WARN_ON_ONCE(!nat)) + return; + + module_put(nat->module); +} +EXPORT_SYMBOL_GPL(nf_nat_helper_put); + struct nf_conn_help * nf_ct_helper_ext_add(struct nf_conn *ct, gfp_t gfp) { @@ -430,6 +497,8 @@ void nf_ct_helper_init(struct nf_conntrack_helper *helper, helper->help = help; helper->from_nlattr = from_nlattr; helper->me = module; + snprintf(helper->nat_mod_name, sizeof(helper->nat_mod_name), + NF_NAT_HELPER_PREFIX "%s", name); if (spec_port == default_port) snprintf(helper->name, sizeof(helper->name), "%s", name); @@ -466,6 +535,22 @@ void nf_conntrack_helpers_unregister(struct nf_conntrack_helper *helper, } EXPORT_SYMBOL_GPL(nf_conntrack_helpers_unregister); +void nf_nat_helper_register(struct nf_conntrack_nat_helper *nat) +{ + mutex_lock(&nf_ct_nat_helpers_mutex); + list_add_rcu(&nat->list, &nf_ct_nat_helpers); + mutex_unlock(&nf_ct_nat_helpers_mutex); +} +EXPORT_SYMBOL_GPL(nf_nat_helper_register); + +void nf_nat_helper_unregister(struct nf_conntrack_nat_helper *nat) +{ + mutex_lock(&nf_ct_nat_helpers_mutex); + list_del_rcu(&nat->list); + mutex_unlock(&nf_ct_nat_helpers_mutex); +} +EXPORT_SYMBOL_GPL(nf_nat_helper_unregister); + static const struct nf_ct_ext_type helper_extend = { .len = sizeof(struct nf_conn_help), .align = __alignof__(struct nf_conn_help), @@ -493,6 +578,7 @@ int nf_conntrack_helper_init(void) goto out_extend; } + INIT_LIST_HEAD(&nf_ct_nat_helpers); return 0; out_extend: kvfree(nf_ct_helper_hash); |