X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;ds=sidebyside;f=net%2Fnetfilter%2Fnf_conntrack_core.c;h=09c0e63110443ccc6358c2255dff3b9006830708;hb=8f03dea52b1d0227656319e1b0822628b43791a8;hp=836541e509fe14e67e04c10012b94ae594c0446b;hpb=40eb006685387b2861bd7196be0ab7144c5d5b71;p=linux-2.6 diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c index 836541e509..09c0e63110 100644 --- a/net/netfilter/nf_conntrack_core.c +++ b/net/netfilter/nf_conntrack_core.c @@ -55,6 +55,7 @@ #include #include #include +#include #include #include @@ -72,87 +73,15 @@ DEFINE_RWLOCK(nf_conntrack_lock); atomic_t nf_conntrack_count = ATOMIC_INIT(0); void (*nf_conntrack_destroyed)(struct nf_conn *conntrack) = NULL; -LIST_HEAD(nf_conntrack_expect_list); -struct nf_conntrack_protocol **nf_ct_protos[PF_MAX] __read_mostly; -struct nf_conntrack_l3proto *nf_ct_l3protos[PF_MAX] __read_mostly; -static LIST_HEAD(helpers); unsigned int nf_conntrack_htable_size __read_mostly = 0; int nf_conntrack_max __read_mostly; struct list_head *nf_conntrack_hash __read_mostly; -static kmem_cache_t *nf_conntrack_expect_cachep __read_mostly; struct nf_conn nf_conntrack_untracked; unsigned int nf_ct_log_invalid __read_mostly; -static LIST_HEAD(unconfirmed); +LIST_HEAD(unconfirmed); static int nf_conntrack_vmalloc __read_mostly; static unsigned int nf_conntrack_next_id; -static unsigned int nf_conntrack_expect_next_id; -#ifdef CONFIG_NF_CONNTRACK_EVENTS -ATOMIC_NOTIFIER_HEAD(nf_conntrack_chain); -ATOMIC_NOTIFIER_HEAD(nf_conntrack_expect_chain); - -DEFINE_PER_CPU(struct nf_conntrack_ecache, nf_conntrack_ecache); - -/* deliver cached events and clear cache entry - must be called with locally - * disabled softirqs */ -static inline void -__nf_ct_deliver_cached_events(struct nf_conntrack_ecache *ecache) -{ - DEBUGP("ecache: delivering events for %p\n", ecache->ct); - if (nf_ct_is_confirmed(ecache->ct) && !nf_ct_is_dying(ecache->ct) - && ecache->events) - atomic_notifier_call_chain(&nf_conntrack_chain, ecache->events, - ecache->ct); - - ecache->events = 0; - nf_ct_put(ecache->ct); - ecache->ct = NULL; -} - -/* Deliver all cached events for a particular conntrack. This is called - * by code prior to async packet handling for freeing the skb */ -void nf_ct_deliver_cached_events(const struct nf_conn *ct) -{ - struct nf_conntrack_ecache *ecache; - - local_bh_disable(); - ecache = &__get_cpu_var(nf_conntrack_ecache); - if (ecache->ct == ct) - __nf_ct_deliver_cached_events(ecache); - local_bh_enable(); -} - -/* Deliver cached events for old pending events, if current conntrack != old */ -void __nf_ct_event_cache_init(struct nf_conn *ct) -{ - struct nf_conntrack_ecache *ecache; - - /* take care of delivering potentially old events */ - ecache = &__get_cpu_var(nf_conntrack_ecache); - BUG_ON(ecache->ct == ct); - if (ecache->ct) - __nf_ct_deliver_cached_events(ecache); - /* initialize for this conntrack/packet */ - ecache->ct = ct; - nf_conntrack_get(&ct->ct_general); -} - -/* flush the event cache - touches other CPU's data and must not be called - * while packets are still passing through the code */ -static void nf_ct_event_cache_flush(void) -{ - struct nf_conntrack_ecache *ecache; - int cpu; - - for_each_possible_cpu(cpu) { - ecache = &per_cpu(nf_conntrack_ecache, cpu); - if (ecache->ct) - nf_ct_put(ecache->ct); - } -} -#else -static inline void nf_ct_event_cache_flush(void) {} -#endif /* CONFIG_NF_CONNTRACK_EVENTS */ DEFINE_PER_CPU(struct ip_conntrack_stat, nf_conntrack_stat); EXPORT_PER_CPU_SYMBOL(nf_conntrack_stat); @@ -184,85 +113,6 @@ DEFINE_RWLOCK(nf_ct_cache_lock); /* This avoids calling kmem_cache_create() with same name simultaneously */ static DEFINE_MUTEX(nf_ct_cache_mutex); -extern struct nf_conntrack_protocol nf_conntrack_generic_protocol; -struct nf_conntrack_protocol * -__nf_ct_proto_find(u_int16_t l3proto, u_int8_t protocol) -{ - if (unlikely(l3proto >= AF_MAX || nf_ct_protos[l3proto] == NULL)) - return &nf_conntrack_generic_protocol; - - return nf_ct_protos[l3proto][protocol]; -} - -/* this is guaranteed to always return a valid protocol helper, since - * it falls back to generic_protocol */ -struct nf_conntrack_protocol * -nf_ct_proto_find_get(u_int16_t l3proto, u_int8_t protocol) -{ - struct nf_conntrack_protocol *p; - - preempt_disable(); - p = __nf_ct_proto_find(l3proto, protocol); - if (!try_module_get(p->me)) - p = &nf_conntrack_generic_protocol; - preempt_enable(); - - return p; -} - -void nf_ct_proto_put(struct nf_conntrack_protocol *p) -{ - module_put(p->me); -} - -struct nf_conntrack_l3proto * -nf_ct_l3proto_find_get(u_int16_t l3proto) -{ - struct nf_conntrack_l3proto *p; - - preempt_disable(); - p = __nf_ct_l3proto_find(l3proto); - if (!try_module_get(p->me)) - p = &nf_conntrack_generic_l3proto; - preempt_enable(); - - return p; -} - -void nf_ct_l3proto_put(struct nf_conntrack_l3proto *p) -{ - module_put(p->me); -} - -int -nf_ct_l3proto_try_module_get(unsigned short l3proto) -{ - int ret; - struct nf_conntrack_l3proto *p; - -retry: p = nf_ct_l3proto_find_get(l3proto); - if (p == &nf_conntrack_generic_l3proto) { - ret = request_module("nf_conntrack-%d", l3proto); - if (!ret) - goto retry; - - return -EPROTOTYPE; - } - - return 0; -} - -void nf_ct_l3proto_module_put(unsigned short l3proto) -{ - struct nf_conntrack_l3proto *p; - - preempt_disable(); - p = __nf_ct_l3proto_find(l3proto); - preempt_enable(); - - module_put(p->me); -} - static int nf_conntrack_hash_rnd_initted; static unsigned int nf_conntrack_hash_rnd; @@ -438,103 +288,6 @@ nf_ct_invert_tuple(struct nf_conntrack_tuple *inverse, return protocol->invert_tuple(inverse, orig); } -/* nf_conntrack_expect helper functions */ -void nf_ct_unlink_expect(struct nf_conntrack_expect *exp) -{ - struct nf_conn_help *master_help = nfct_help(exp->master); - - NF_CT_ASSERT(master_help); - ASSERT_WRITE_LOCK(&nf_conntrack_lock); - NF_CT_ASSERT(!timer_pending(&exp->timeout)); - - list_del(&exp->list); - NF_CT_STAT_INC(expect_delete); - master_help->expecting--; - nf_conntrack_expect_put(exp); -} - -static void expectation_timed_out(unsigned long ul_expect) -{ - struct nf_conntrack_expect *exp = (void *)ul_expect; - - write_lock_bh(&nf_conntrack_lock); - nf_ct_unlink_expect(exp); - write_unlock_bh(&nf_conntrack_lock); - nf_conntrack_expect_put(exp); -} - -struct nf_conntrack_expect * -__nf_conntrack_expect_find(const struct nf_conntrack_tuple *tuple) -{ - struct nf_conntrack_expect *i; - - list_for_each_entry(i, &nf_conntrack_expect_list, list) { - if (nf_ct_tuple_mask_cmp(tuple, &i->tuple, &i->mask)) { - atomic_inc(&i->use); - return i; - } - } - return NULL; -} - -/* Just find a expectation corresponding to a tuple. */ -struct nf_conntrack_expect * -nf_conntrack_expect_find(const struct nf_conntrack_tuple *tuple) -{ - struct nf_conntrack_expect *i; - - read_lock_bh(&nf_conntrack_lock); - i = __nf_conntrack_expect_find(tuple); - read_unlock_bh(&nf_conntrack_lock); - - return i; -} - -/* If an expectation for this connection is found, it gets delete from - * global list then returned. */ -static struct nf_conntrack_expect * -find_expectation(const struct nf_conntrack_tuple *tuple) -{ - struct nf_conntrack_expect *i; - - list_for_each_entry(i, &nf_conntrack_expect_list, list) { - /* If master is not in hash table yet (ie. packet hasn't left - this machine yet), how can other end know about expected? - Hence these are not the droids you are looking for (if - master ct never got confirmed, we'd hold a reference to it - and weird things would happen to future packets). */ - if (nf_ct_tuple_mask_cmp(tuple, &i->tuple, &i->mask) - && nf_ct_is_confirmed(i->master)) { - if (i->flags & NF_CT_EXPECT_PERMANENT) { - atomic_inc(&i->use); - return i; - } else if (del_timer(&i->timeout)) { - nf_ct_unlink_expect(i); - return i; - } - } - } - return NULL; -} - -/* delete all expectations for this conntrack */ -void nf_ct_remove_expectations(struct nf_conn *ct) -{ - struct nf_conntrack_expect *i, *tmp; - struct nf_conn_help *help = nfct_help(ct); - - /* Optimization: most connection never expect any others. */ - if (!help || help->expecting == 0) - return; - - list_for_each_entry_safe(i, tmp, &nf_conntrack_expect_list, list) { - if (i->master == ct && del_timer(&i->timeout)) { - nf_ct_unlink_expect(i); - nf_conntrack_expect_put(i); - } - } -} - static void clean_from_lists(struct nf_conn *ct) { @@ -794,46 +547,6 @@ static int early_drop(struct list_head *chain) return dropped; } -static struct nf_conntrack_helper * -__nf_ct_helper_find(const struct nf_conntrack_tuple *tuple) -{ - struct nf_conntrack_helper *h; - - list_for_each_entry(h, &helpers, list) { - if (nf_ct_tuple_mask_cmp(tuple, &h->tuple, &h->mask)) - return h; - } - return NULL; -} - -struct nf_conntrack_helper * -nf_ct_helper_find_get( const struct nf_conntrack_tuple *tuple) -{ - struct nf_conntrack_helper *helper; - - /* need nf_conntrack_lock to assure that helper exists until - * try_module_get() is called */ - read_lock_bh(&nf_conntrack_lock); - - helper = __nf_ct_helper_find(tuple); - if (helper) { - /* need to increase module usage count to assure helper will - * not go away while the caller is e.g. busy putting a - * conntrack in the hash that uses the helper */ - if (!try_module_get(helper->me)) - helper = NULL; - } - - read_unlock_bh(&nf_conntrack_lock); - - return helper; -} - -void nf_ct_helper_put(struct nf_conntrack_helper *helper) -{ - module_put(helper->me); -} - static struct nf_conn * __nf_conntrack_alloc(const struct nf_conntrack_tuple *orig, const struct nf_conntrack_tuple *repl, @@ -893,12 +606,6 @@ __nf_conntrack_alloc(const struct nf_conntrack_tuple *orig, memset(conntrack, 0, nf_ct_cache[features].size); conntrack->features = features; - if (helper) { - struct nf_conn_help *help = nfct_help(conntrack); - NF_CT_ASSERT(help); - help->helper = helper; - } - atomic_set(&conntrack->ct_general.use, 1); conntrack->ct_general.destroy = destroy_conntrack; conntrack->tuplehash[IP_CT_DIR_ORIGINAL].tuple = *orig; @@ -982,8 +689,13 @@ init_conntrack(const struct nf_conntrack_tuple *tuple, #endif nf_conntrack_get(&conntrack->master->ct_general); NF_CT_STAT_INC(expect_new); - } else + } else { + struct nf_conn_help *help = nfct_help(conntrack); + + if (help) + help->helper = __nf_ct_helper_find(&repl_tuple); NF_CT_STAT_INC(new); + } /* Overload tuple linked list to put us in unconfirmed list. */ list_add(&conntrack->tuplehash[IP_CT_DIR_ORIGINAL].list, &unconfirmed); @@ -1134,246 +846,6 @@ int nf_ct_invert_tuplepr(struct nf_conntrack_tuple *inverse, orig->dst.protonum)); } -/* 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_add(&me->list, &helpers); - 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 void 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; - } -} - -void nf_conntrack_helper_unregister(struct nf_conntrack_helper *me) -{ - unsigned int i; - struct nf_conntrack_tuple_hash *h; - struct nf_conntrack_expect *exp, *tmp; - - /* Need write lock here, to delete helper. */ - write_lock_bh(&nf_conntrack_lock); - list_del(&me->list); - - /* 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_for_each_entry(h, &unconfirmed, list) - unhelp(h, me); - for (i = 0; i < nf_conntrack_htable_size; i++) { - list_for_each_entry(h, &nf_conntrack_hash[i], list) - unhelp(h, me); - } - write_unlock_bh(&nf_conntrack_lock); - - /* Someone could be still looking at the helper in a bh. */ - synchronize_net(); -} - /* Refresh conntrack for this many jiffies and do accounting if do_acct is 1 */ void __nf_ct_refresh_acct(struct nf_conn *ct, enum ip_conntrack_info ctinfo,