diff --git a/include/net/netfilter/nf_conntrack_helper.h b/include/net/netfilter/nf_conntrack_helper.h index f8060ab5a0839d39373249d778db5b8e1fbe6830..66d65a7caa394164776c8559d3c5bd41c55bc8d8 100644 --- a/include/net/netfilter/nf_conntrack_helper.h +++ b/include/net/netfilter/nf_conntrack_helper.h @@ -38,9 +38,6 @@ struct nf_conntrack_helper unsigned int expect_class_max; }; -extern struct nf_conntrack_helper * -__nf_ct_helper_find(const struct nf_conntrack_tuple *tuple); - extern struct nf_conntrack_helper * __nf_conntrack_helper_find_byname(const char *name); @@ -49,6 +46,8 @@ extern void nf_conntrack_helper_unregister(struct nf_conntrack_helper *); extern struct nf_conn_help *nf_ct_helper_ext_add(struct nf_conn *ct, gfp_t gfp); +extern int __nf_ct_try_assign_helper(struct nf_conn *ct, gfp_t flags); + static inline struct nf_conn_help *nfct_help(const struct nf_conn *ct) { return nf_ct_ext_find(ct, NF_CT_EXT_HELPER); diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c index 622d7c671cb78533082f9bf0b655a3bbffcd2f92..1e649fb9e0df2faba34e4f7bde17ffb1ab51fe68 100644 --- a/net/netfilter/nf_conntrack_core.c +++ b/net/netfilter/nf_conntrack_core.c @@ -588,14 +588,7 @@ init_conntrack(struct net *net, nf_conntrack_get(&ct->master->ct_general); NF_CT_STAT_INC(net, expect_new); } else { - struct nf_conntrack_helper *helper; - - helper = __nf_ct_helper_find(&repl_tuple); - if (helper) { - help = nf_ct_helper_ext_add(ct, GFP_ATOMIC); - if (help) - rcu_assign_pointer(help->helper, helper); - } + __nf_ct_try_assign_helper(ct, GFP_ATOMIC); NF_CT_STAT_INC(net, new); } @@ -772,7 +765,6 @@ void nf_conntrack_alter_reply(struct nf_conn *ct, const struct nf_conntrack_tuple *newreply) { struct nf_conn_help *help = nfct_help(ct); - struct nf_conntrack_helper *helper; /* Should be unconfirmed, so not in hash table yet */ NF_CT_ASSERT(!nf_ct_is_confirmed(ct)); @@ -785,23 +777,7 @@ void nf_conntrack_alter_reply(struct nf_conn *ct, return; rcu_read_lock(); - helper = __nf_ct_helper_find(newreply); - if (helper == NULL) { - if (help) - rcu_assign_pointer(help->helper, NULL); - goto out; - } - - if (help == NULL) { - help = nf_ct_helper_ext_add(ct, GFP_ATOMIC); - if (help == NULL) - goto out; - } else { - memset(&help->help, 0, sizeof(help->help)); - } - - rcu_assign_pointer(help->helper, helper); -out: + __nf_ct_try_assign_helper(ct, GFP_ATOMIC); rcu_read_unlock(); } EXPORT_SYMBOL_GPL(nf_conntrack_alter_reply); diff --git a/net/netfilter/nf_conntrack_helper.c b/net/netfilter/nf_conntrack_helper.c index 9c06b9f86ad45a524c2b3e2fe1b522930ca70af0..9e4b74b95ce813e1dedd3b5ebe16a88ed39d3a57 100644 --- a/net/netfilter/nf_conntrack_helper.c +++ b/net/netfilter/nf_conntrack_helper.c @@ -44,7 +44,7 @@ static unsigned int helper_hash(const struct nf_conntrack_tuple *tuple) (__force __u16)tuple->src.u.all) % nf_ct_helper_hsize; } -struct nf_conntrack_helper * +static struct nf_conntrack_helper * __nf_ct_helper_find(const struct nf_conntrack_tuple *tuple) { struct nf_conntrack_helper *helper; @@ -62,7 +62,6 @@ __nf_ct_helper_find(const struct nf_conntrack_tuple *tuple) } return NULL; } -EXPORT_SYMBOL_GPL(__nf_ct_helper_find); struct nf_conntrack_helper * __nf_conntrack_helper_find_byname(const char *name) @@ -94,6 +93,35 @@ struct nf_conn_help *nf_ct_helper_ext_add(struct nf_conn *ct, gfp_t gfp) } EXPORT_SYMBOL_GPL(nf_ct_helper_ext_add); +int __nf_ct_try_assign_helper(struct nf_conn *ct, gfp_t flags) +{ + int ret = 0; + struct nf_conntrack_helper *helper; + struct nf_conn_help *help = nfct_help(ct); + + helper = __nf_ct_helper_find(&ct->tuplehash[IP_CT_DIR_REPLY].tuple); + if (helper == NULL) { + if (help) + rcu_assign_pointer(help->helper, NULL); + goto out; + } + + if (help == NULL) { + help = nf_ct_helper_ext_add(ct, flags); + if (help == NULL) { + ret = -ENOMEM; + goto out; + } + } else { + memset(&help->help, 0, sizeof(help->help)); + } + + rcu_assign_pointer(help->helper, helper); +out: + return ret; +} +EXPORT_SYMBOL_GPL(__nf_ct_try_assign_helper); + static inline int unhelp(struct nf_conntrack_tuple_hash *i, const struct nf_conntrack_helper *me) { diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c index 49a04fa0becc7a7bdad0ee5d520aef7394b5ae24..4f6486cfd337db43e9d74255d28000353c59d54a 100644 --- a/net/netfilter/nf_conntrack_netlink.c +++ b/net/netfilter/nf_conntrack_netlink.c @@ -917,8 +917,22 @@ ctnetlink_change_helper(struct nf_conn *ct, struct nlattr *cda[]) } helper = __nf_conntrack_helper_find_byname(helpname); - if (helper == NULL) + if (helper == NULL) { +#ifdef CONFIG_MODULES + spin_unlock_bh(&nf_conntrack_lock); + + if (request_module("nfct-helper-%s", helpname) < 0) { + spin_lock_bh(&nf_conntrack_lock); + return -EOPNOTSUPP; + } + + spin_lock_bh(&nf_conntrack_lock); + helper = __nf_conntrack_helper_find_byname(helpname); + if (helper) + return -EAGAIN; +#endif return -EOPNOTSUPP; + } if (help) { if (help->helper == helper) @@ -1082,7 +1096,6 @@ ctnetlink_create_conntrack(struct nlattr *cda[], { struct nf_conn *ct; int err = -EINVAL; - struct nf_conn_help *help; struct nf_conntrack_helper *helper; ct = nf_conntrack_alloc(&init_net, otuple, rtuple, GFP_KERNEL); @@ -1097,16 +1110,55 @@ ctnetlink_create_conntrack(struct nlattr *cda[], ct->status |= IPS_CONFIRMED; rcu_read_lock(); - helper = __nf_ct_helper_find(rtuple); - if (helper) { - help = nf_ct_helper_ext_add(ct, GFP_ATOMIC); - if (help == NULL) { + if (cda[CTA_HELP]) { + char *helpname; + + err = ctnetlink_parse_help(cda[CTA_HELP], &helpname); + if (err < 0) { + rcu_read_unlock(); + goto err; + } + + helper = __nf_conntrack_helper_find_byname(helpname); + if (helper == NULL) { + rcu_read_unlock(); +#ifdef CONFIG_MODULES + if (request_module("nfct-helper-%s", helpname) < 0) { + err = -EOPNOTSUPP; + goto err; + } + + rcu_read_lock(); + helper = __nf_conntrack_helper_find_byname(helpname); + if (helper) { + rcu_read_unlock(); + err = -EAGAIN; + goto err; + } + rcu_read_unlock(); +#endif + err = -EOPNOTSUPP; + goto err; + } else { + struct nf_conn_help *help; + + help = nf_ct_helper_ext_add(ct, GFP_ATOMIC); + if (help == NULL) { + rcu_read_unlock(); + err = -ENOMEM; + goto err; + } + + /* not in hash table yet so not strictly necessary */ + rcu_assign_pointer(help->helper, helper); + } + } else { + /* try an implicit helper assignation */ + err = __nf_ct_try_assign_helper(ct, GFP_ATOMIC); + if (err < 0) { rcu_read_unlock(); - err = -ENOMEM; goto err; } - /* not in hash table yet so not strictly necessary */ - rcu_assign_pointer(help->helper, helper); } if (cda[CTA_STATUS]) {