-/* Would two expected things clash? */
-static inline int expect_clash(const struct nf_conntrack_expect *a,
- const struct nf_conntrack_expect *b)
-{
- /* Part covered by intersection of masks must be unequal,
- otherwise they clash */
- struct nf_conntrack_tuple intersect_mask;
- int count;
-
- intersect_mask.src.l3num = a->mask.src.l3num & b->mask.src.l3num;
- intersect_mask.src.u.all = a->mask.src.u.all & b->mask.src.u.all;
- intersect_mask.dst.u.all = a->mask.dst.u.all & b->mask.dst.u.all;
- intersect_mask.dst.protonum = a->mask.dst.protonum
- & b->mask.dst.protonum;
-
- for (count = 0; count < NF_CT_TUPLE_L3SIZE; count++){
- intersect_mask.src.u3.all[count] =
- a->mask.src.u3.all[count] & b->mask.src.u3.all[count];
- }
-
- for (count = 0; count < NF_CT_TUPLE_L3SIZE; count++){
- intersect_mask.dst.u3.all[count] =
- a->mask.dst.u3.all[count] & b->mask.dst.u3.all[count];
- }
-
- return nf_ct_tuple_mask_cmp(&a->tuple, &b->tuple, &intersect_mask);
-}
-
-static inline int expect_matches(const struct nf_conntrack_expect *a,
- const struct nf_conntrack_expect *b)
-{
- return a->master == b->master
- && nf_ct_tuple_equal(&a->tuple, &b->tuple)
- && nf_ct_tuple_equal(&a->mask, &b->mask);
-}
-
-/* Generally a bad idea to call this: could have matched already. */
-void nf_conntrack_unexpect_related(struct nf_conntrack_expect *exp)
-{
- struct nf_conntrack_expect *i;
-
- write_lock_bh(&nf_conntrack_lock);
- /* choose the the oldest expectation to evict */
- list_for_each_entry_reverse(i, &nf_conntrack_expect_list, list) {
- if (expect_matches(i, exp) && del_timer(&i->timeout)) {
- nf_ct_unlink_expect(i);
- write_unlock_bh(&nf_conntrack_lock);
- nf_conntrack_expect_put(i);
- return;
- }
- }
- write_unlock_bh(&nf_conntrack_lock);
-}
-
-/* We don't increase the master conntrack refcount for non-fulfilled
- * conntracks. During the conntrack destruction, the expectations are
- * always killed before the conntrack itself */
-struct nf_conntrack_expect *nf_conntrack_expect_alloc(struct nf_conn *me)
-{
- struct nf_conntrack_expect *new;
-
- new = kmem_cache_alloc(nf_conntrack_expect_cachep, GFP_ATOMIC);
- if (!new) {
- DEBUGP("expect_related: OOM allocating expect\n");
- return NULL;
- }
- new->master = me;
- atomic_set(&new->use, 1);
- return new;
-}
-
-void nf_conntrack_expect_put(struct nf_conntrack_expect *exp)
-{
- if (atomic_dec_and_test(&exp->use))
- kmem_cache_free(nf_conntrack_expect_cachep, exp);
-}
-
-static void nf_conntrack_expect_insert(struct nf_conntrack_expect *exp)
-{
- struct nf_conn_help *master_help = nfct_help(exp->master);
-
- atomic_inc(&exp->use);
- master_help->expecting++;
- list_add(&exp->list, &nf_conntrack_expect_list);
-
- init_timer(&exp->timeout);
- exp->timeout.data = (unsigned long)exp;
- exp->timeout.function = expectation_timed_out;
- exp->timeout.expires = jiffies + master_help->helper->timeout * HZ;
- add_timer(&exp->timeout);
-
- exp->id = ++nf_conntrack_expect_next_id;
- atomic_inc(&exp->use);
- NF_CT_STAT_INC(expect_create);
-}
-
-/* Race with expectations being used means we could have none to find; OK. */
-static void evict_oldest_expect(struct nf_conn *master)
-{
- struct nf_conntrack_expect *i;
-
- list_for_each_entry_reverse(i, &nf_conntrack_expect_list, list) {
- if (i->master == master) {
- if (del_timer(&i->timeout)) {
- nf_ct_unlink_expect(i);
- nf_conntrack_expect_put(i);
- }
- break;
- }
- }
-}
-
-static inline int refresh_timer(struct nf_conntrack_expect *i)
-{
- struct nf_conn_help *master_help = nfct_help(i->master);
-
- if (!del_timer(&i->timeout))
- return 0;
-
- i->timeout.expires = jiffies + master_help->helper->timeout*HZ;
- add_timer(&i->timeout);
- return 1;
-}
-
-int nf_conntrack_expect_related(struct nf_conntrack_expect *expect)
-{
- struct nf_conntrack_expect *i;
- struct nf_conn *master = expect->master;
- struct nf_conn_help *master_help = nfct_help(master);
- int ret;
-
- NF_CT_ASSERT(master_help);
-
- DEBUGP("nf_conntrack_expect_related %p\n", related_to);
- DEBUGP("tuple: "); NF_CT_DUMP_TUPLE(&expect->tuple);
- DEBUGP("mask: "); NF_CT_DUMP_TUPLE(&expect->mask);
-
- write_lock_bh(&nf_conntrack_lock);
- list_for_each_entry(i, &nf_conntrack_expect_list, list) {
- if (expect_matches(i, expect)) {
- /* Refresh timer: if it's dying, ignore.. */
- if (refresh_timer(i)) {
- ret = 0;
- goto out;
- }
- } else if (expect_clash(i, expect)) {
- ret = -EBUSY;
- goto out;
- }
- }
- /* Will be over limit? */
- if (master_help->helper->max_expected &&
- master_help->expecting >= master_help->helper->max_expected)
- evict_oldest_expect(master);
-
- nf_conntrack_expect_insert(expect);
- nf_conntrack_expect_event(IPEXP_NEW, expect);
- ret = 0;
-out:
- write_unlock_bh(&nf_conntrack_lock);
- return ret;
-}
-
-int nf_conntrack_helper_register(struct nf_conntrack_helper *me)
-{
- int ret;
- BUG_ON(me->timeout == 0);
-
- ret = nf_conntrack_register_cache(NF_CT_F_HELP, "nf_conntrack:help",
- sizeof(struct nf_conn)
- + sizeof(struct nf_conn_help)
- + __alignof__(struct nf_conn_help));
- if (ret < 0) {
- printk(KERN_ERR "nf_conntrack_helper_reigster: Unable to create slab cache for conntracks\n");
- return ret;
- }
- write_lock_bh(&nf_conntrack_lock);
- list_prepend(&helpers, me);
- write_unlock_bh(&nf_conntrack_lock);
-
- return 0;
-}
-
-struct nf_conntrack_helper *
-__nf_conntrack_helper_find_byname(const char *name)
-{
- struct nf_conntrack_helper *h;
-
- list_for_each_entry(h, &helpers, list) {
- if (!strcmp(h->name, name))
- return h;
- }
-
- return NULL;
-}
-
-static inline int unhelp(struct nf_conntrack_tuple_hash *i,
- const struct nf_conntrack_helper *me)
-{
- struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(i);
- struct nf_conn_help *help = nfct_help(ct);
-
- if (help && help->helper == me) {
- nf_conntrack_event(IPCT_HELPER, ct);
- help->helper = NULL;
- }
- return 0;
-}
-
-void nf_conntrack_helper_unregister(struct nf_conntrack_helper *me)
-{
- unsigned int i;
- struct nf_conntrack_expect *exp, *tmp;
-
- /* Need write lock here, to delete helper. */
- write_lock_bh(&nf_conntrack_lock);
- LIST_DELETE(&helpers, me);
-
- /* Get rid of expectations */
- list_for_each_entry_safe(exp, tmp, &nf_conntrack_expect_list, list) {
- struct nf_conn_help *help = nfct_help(exp->master);
- if (help->helper == me && del_timer(&exp->timeout)) {
- nf_ct_unlink_expect(exp);
- nf_conntrack_expect_put(exp);
- }
- }
-
- /* Get rid of expecteds, set helpers to NULL. */
- LIST_FIND_W(&unconfirmed, unhelp, struct nf_conntrack_tuple_hash*, me);
- for (i = 0; i < nf_conntrack_htable_size; i++)
- LIST_FIND_W(&nf_conntrack_hash[i], unhelp,
- struct nf_conntrack_tuple_hash *, me);
- write_unlock_bh(&nf_conntrack_lock);
-
- /* Someone could be still looking at the helper in a bh. */
- synchronize_net();
-}
-