diff options
Diffstat (limited to 'net/netfilter/nf_conntrack_core.c')
-rw-r--r-- | net/netfilter/nf_conntrack_core.c | 123 |
1 files changed, 70 insertions, 53 deletions
diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c index 54e983f13898..c55bbdc7d429 100644 --- a/net/netfilter/nf_conntrack_core.c +++ b/net/netfilter/nf_conntrack_core.c @@ -29,6 +29,7 @@ #include <linux/netdevice.h> #include <linux/socket.h> #include <linux/mm.h> +#include <linux/rculist_nulls.h> #include <net/netfilter/nf_conntrack.h> #include <net/netfilter/nf_conntrack_l3proto.h> @@ -163,8 +164,8 @@ static void clean_from_lists(struct nf_conn *ct) { pr_debug("clean_from_lists(%p)\n", ct); - hlist_del_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnode); - hlist_del_rcu(&ct->tuplehash[IP_CT_DIR_REPLY].hnode); + hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode); + hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_REPLY].hnnode); /* Destroy all pending expectations */ nf_ct_remove_expectations(ct); @@ -204,8 +205,8 @@ destroy_conntrack(struct nf_conntrack *nfct) /* We overload first tuple to link into unconfirmed list. */ if (!nf_ct_is_confirmed(ct)) { - BUG_ON(hlist_unhashed(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnode)); - hlist_del(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnode); + BUG_ON(hlist_nulls_unhashed(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode)); + hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode); } NF_CT_STAT_INC(net, delete); @@ -242,18 +243,26 @@ static void death_by_timeout(unsigned long ul_conntrack) nf_ct_put(ct); } +/* + * Warning : + * - Caller must take a reference on returned object + * and recheck nf_ct_tuple_equal(tuple, &h->tuple) + * OR + * - Caller must lock nf_conntrack_lock before calling this function + */ struct nf_conntrack_tuple_hash * __nf_conntrack_find(struct net *net, const struct nf_conntrack_tuple *tuple) { struct nf_conntrack_tuple_hash *h; - struct hlist_node *n; + struct hlist_nulls_node *n; unsigned int hash = hash_conntrack(tuple); /* Disable BHs the entire time since we normally need to disable them * at least once for the stats anyway. */ local_bh_disable(); - hlist_for_each_entry_rcu(h, n, &net->ct.hash[hash], hnode) { +begin: + hlist_nulls_for_each_entry_rcu(h, n, &net->ct.hash[hash], hnnode) { if (nf_ct_tuple_equal(tuple, &h->tuple)) { NF_CT_STAT_INC(net, found); local_bh_enable(); @@ -261,6 +270,13 @@ __nf_conntrack_find(struct net *net, const struct nf_conntrack_tuple *tuple) } NF_CT_STAT_INC(net, searched); } + /* + * if the nulls value we got at the end of this lookup is + * not the expected one, we must restart lookup. + * We probably met an item that was moved to another chain. + */ + if (get_nulls_value(n) != hash) + goto begin; local_bh_enable(); return NULL; @@ -275,11 +291,18 @@ nf_conntrack_find_get(struct net *net, const struct nf_conntrack_tuple *tuple) struct nf_conn *ct; rcu_read_lock(); +begin: h = __nf_conntrack_find(net, tuple); if (h) { ct = nf_ct_tuplehash_to_ctrack(h); if (unlikely(!atomic_inc_not_zero(&ct->ct_general.use))) h = NULL; + else { + if (unlikely(!nf_ct_tuple_equal(tuple, &h->tuple))) { + nf_ct_put(ct); + goto begin; + } + } } rcu_read_unlock(); @@ -293,9 +316,9 @@ static void __nf_conntrack_hash_insert(struct nf_conn *ct, { struct net *net = nf_ct_net(ct); - hlist_add_head_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnode, + hlist_nulls_add_head_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode, &net->ct.hash[hash]); - hlist_add_head_rcu(&ct->tuplehash[IP_CT_DIR_REPLY].hnode, + hlist_nulls_add_head_rcu(&ct->tuplehash[IP_CT_DIR_REPLY].hnnode, &net->ct.hash[repl_hash]); } @@ -318,7 +341,7 @@ __nf_conntrack_confirm(struct sk_buff *skb) struct nf_conntrack_tuple_hash *h; struct nf_conn *ct; struct nf_conn_help *help; - struct hlist_node *n; + struct hlist_nulls_node *n; enum ip_conntrack_info ctinfo; struct net *net; @@ -350,17 +373,17 @@ __nf_conntrack_confirm(struct sk_buff *skb) /* See if there's one in the list already, including reverse: NAT could have grabbed it without realizing, since we're not in the hash. If there is, we lost race. */ - hlist_for_each_entry(h, n, &net->ct.hash[hash], hnode) + hlist_nulls_for_each_entry(h, n, &net->ct.hash[hash], hnnode) if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple, &h->tuple)) goto out; - hlist_for_each_entry(h, n, &net->ct.hash[repl_hash], hnode) + hlist_nulls_for_each_entry(h, n, &net->ct.hash[repl_hash], hnnode) if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_REPLY].tuple, &h->tuple)) goto out; /* Remove from unconfirmed list */ - hlist_del(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnode); + hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode); __nf_conntrack_hash_insert(ct, hash, repl_hash); /* Timer relative to confirmation time, not original @@ -399,14 +422,14 @@ nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple, { struct net *net = nf_ct_net(ignored_conntrack); struct nf_conntrack_tuple_hash *h; - struct hlist_node *n; + struct hlist_nulls_node *n; unsigned int hash = hash_conntrack(tuple); /* Disable BHs the entire time since we need to disable them at * least once for the stats anyway. */ rcu_read_lock_bh(); - hlist_for_each_entry_rcu(h, n, &net->ct.hash[hash], hnode) { + hlist_nulls_for_each_entry_rcu(h, n, &net->ct.hash[hash], hnnode) { if (nf_ct_tuplehash_to_ctrack(h) != ignored_conntrack && nf_ct_tuple_equal(tuple, &h->tuple)) { NF_CT_STAT_INC(net, found); @@ -430,14 +453,14 @@ static noinline int early_drop(struct net *net, unsigned int hash) /* Use oldest entry, which is roughly LRU */ struct nf_conntrack_tuple_hash *h; struct nf_conn *ct = NULL, *tmp; - struct hlist_node *n; + struct hlist_nulls_node *n; unsigned int i, cnt = 0; int dropped = 0; rcu_read_lock(); for (i = 0; i < nf_conntrack_htable_size; i++) { - hlist_for_each_entry_rcu(h, n, &net->ct.hash[hash], - hnode) { + hlist_nulls_for_each_entry_rcu(h, n, &net->ct.hash[hash], + hnnode) { tmp = nf_ct_tuplehash_to_ctrack(h); if (!test_bit(IPS_ASSURED_BIT, &tmp->status)) ct = tmp; @@ -508,27 +531,19 @@ struct nf_conn *nf_conntrack_alloc(struct net *net, #ifdef CONFIG_NET_NS ct->ct_net = net; #endif - INIT_RCU_HEAD(&ct->rcu); return ct; } EXPORT_SYMBOL_GPL(nf_conntrack_alloc); -static void nf_conntrack_free_rcu(struct rcu_head *head) -{ - struct nf_conn *ct = container_of(head, struct nf_conn, rcu); - - nf_ct_ext_free(ct); - kmem_cache_free(nf_conntrack_cachep, ct); -} - void nf_conntrack_free(struct nf_conn *ct) { struct net *net = nf_ct_net(ct); nf_ct_ext_destroy(ct); atomic_dec(&net->ct.count); - call_rcu(&ct->rcu, nf_conntrack_free_rcu); + nf_ct_ext_free(ct); + kmem_cache_free(nf_conntrack_cachep, ct); } EXPORT_SYMBOL_GPL(nf_conntrack_free); @@ -594,7 +609,7 @@ init_conntrack(struct net *net, } /* Overload tuple linked list to put us in unconfirmed list. */ - hlist_add_head(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnode, + hlist_nulls_add_head_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode, &net->ct.unconfirmed); spin_unlock_bh(&nf_conntrack_lock); @@ -934,17 +949,17 @@ get_next_corpse(struct net *net, int (*iter)(struct nf_conn *i, void *data), { struct nf_conntrack_tuple_hash *h; struct nf_conn *ct; - struct hlist_node *n; + struct hlist_nulls_node *n; spin_lock_bh(&nf_conntrack_lock); for (; *bucket < nf_conntrack_htable_size; (*bucket)++) { - hlist_for_each_entry(h, n, &net->ct.hash[*bucket], hnode) { + hlist_nulls_for_each_entry(h, n, &net->ct.hash[*bucket], hnnode) { ct = nf_ct_tuplehash_to_ctrack(h); if (iter(ct, data)) goto found; } } - hlist_for_each_entry(h, n, &net->ct.unconfirmed, hnode) { + hlist_nulls_for_each_entry(h, n, &net->ct.unconfirmed, hnnode) { ct = nf_ct_tuplehash_to_ctrack(h); if (iter(ct, data)) set_bit(IPS_DYING_BIT, &ct->status); @@ -992,7 +1007,7 @@ static int kill_all(struct nf_conn *i, void *data) return 1; } -void nf_ct_free_hashtable(struct hlist_head *hash, int vmalloced, unsigned int size) +void nf_ct_free_hashtable(void *hash, int vmalloced, unsigned int size) { if (vmalloced) vfree(hash); @@ -1060,26 +1075,28 @@ void nf_conntrack_cleanup(struct net *net) } } -struct hlist_head *nf_ct_alloc_hashtable(unsigned int *sizep, int *vmalloced) +void *nf_ct_alloc_hashtable(unsigned int *sizep, int *vmalloced, int nulls) { - struct hlist_head *hash; - unsigned int size, i; + struct hlist_nulls_head *hash; + unsigned int nr_slots, i; + size_t sz; *vmalloced = 0; - size = *sizep = roundup(*sizep, PAGE_SIZE / sizeof(struct hlist_head)); - hash = (void*)__get_free_pages(GFP_KERNEL|__GFP_NOWARN, - get_order(sizeof(struct hlist_head) - * size)); + BUILD_BUG_ON(sizeof(struct hlist_nulls_head) != sizeof(struct hlist_head)); + nr_slots = *sizep = roundup(*sizep, PAGE_SIZE / sizeof(struct hlist_nulls_head)); + sz = nr_slots * sizeof(struct hlist_nulls_head); + hash = (void *)__get_free_pages(GFP_KERNEL | __GFP_NOWARN | __GFP_ZERO, + get_order(sz)); if (!hash) { *vmalloced = 1; printk(KERN_WARNING "nf_conntrack: falling back to vmalloc.\n"); - hash = vmalloc(sizeof(struct hlist_head) * size); + hash = __vmalloc(sz, GFP_KERNEL | __GFP_ZERO, PAGE_KERNEL); } - if (hash) - for (i = 0; i < size; i++) - INIT_HLIST_HEAD(&hash[i]); + if (hash && nulls) + for (i = 0; i < nr_slots; i++) + INIT_HLIST_NULLS_HEAD(&hash[i], i); return hash; } @@ -1090,7 +1107,7 @@ int nf_conntrack_set_hashsize(const char *val, struct kernel_param *kp) int i, bucket, vmalloced, old_vmalloced; unsigned int hashsize, old_size; int rnd; - struct hlist_head *hash, *old_hash; + struct hlist_nulls_head *hash, *old_hash; struct nf_conntrack_tuple_hash *h; /* On boot, we can set this without any fancy locking. */ @@ -1101,7 +1118,7 @@ int nf_conntrack_set_hashsize(const char *val, struct kernel_param *kp) if (!hashsize) return -EINVAL; - hash = nf_ct_alloc_hashtable(&hashsize, &vmalloced); + hash = nf_ct_alloc_hashtable(&hashsize, &vmalloced, 1); if (!hash) return -ENOMEM; @@ -1116,12 +1133,12 @@ int nf_conntrack_set_hashsize(const char *val, struct kernel_param *kp) */ spin_lock_bh(&nf_conntrack_lock); for (i = 0; i < nf_conntrack_htable_size; i++) { - while (!hlist_empty(&init_net.ct.hash[i])) { - h = hlist_entry(init_net.ct.hash[i].first, - struct nf_conntrack_tuple_hash, hnode); - hlist_del_rcu(&h->hnode); + while (!hlist_nulls_empty(&init_net.ct.hash[i])) { + h = hlist_nulls_entry(init_net.ct.hash[i].first, + struct nf_conntrack_tuple_hash, hnnode); + hlist_nulls_del_rcu(&h->hnnode); bucket = __hash_conntrack(&h->tuple, hashsize, rnd); - hlist_add_head_rcu(&h->hnode, &hash[bucket]); + hlist_nulls_add_head_rcu(&h->hnnode, &hash[bucket]); } } old_size = nf_conntrack_htable_size; @@ -1172,7 +1189,7 @@ static int nf_conntrack_init_init_net(void) nf_conntrack_cachep = kmem_cache_create("nf_conntrack", sizeof(struct nf_conn), - 0, 0, NULL); + 0, SLAB_DESTROY_BY_RCU, NULL); if (!nf_conntrack_cachep) { printk(KERN_ERR "Unable to create nf_conn slab cache\n"); ret = -ENOMEM; @@ -1202,7 +1219,7 @@ static int nf_conntrack_init_net(struct net *net) int ret; atomic_set(&net->ct.count, 0); - INIT_HLIST_HEAD(&net->ct.unconfirmed); + INIT_HLIST_NULLS_HEAD(&net->ct.unconfirmed, 0); net->ct.stat = alloc_percpu(struct ip_conntrack_stat); if (!net->ct.stat) { ret = -ENOMEM; @@ -1212,7 +1229,7 @@ static int nf_conntrack_init_net(struct net *net) if (ret < 0) goto err_ecache; net->ct.hash = nf_ct_alloc_hashtable(&nf_conntrack_htable_size, - &net->ct.hash_vmalloc); + &net->ct.hash_vmalloc, 1); if (!net->ct.hash) { ret = -ENOMEM; printk(KERN_ERR "Unable to create nf_conntrack_hash\n"); |