mac80211: fix another race in aggregation start
[linux-2.6.git] / net / netfilter / xt_connlimit.c
index 26997ce..c6d5a83 100644 (file)
@@ -5,18 +5,19 @@
  *   Nov 2002: Martin Bene <martin.bene@icomedias.com>:
  *             only ignore TIME_WAIT or gone connections
  *   (C) CC Computer Consultants GmbH, 2007
- *   Contact: <jengelh@computergmbh.de>
  *
  * based on ...
  *
  * Kernel module to match connection tracking information.
  * GPL (C) 1999  Rusty Russell (rusty@rustcorp.com.au).
  */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 #include <linux/in.h>
 #include <linux/in6.h>
 #include <linux/ip.h>
 #include <linux/ipv6.h>
 #include <linux/jhash.h>
+#include <linux/slab.h>
 #include <linux/list.h>
 #include <linux/module.h>
 #include <linux/random.h>
 
 /* we will save the tuples of all connections we care about */
 struct xt_connlimit_conn {
-       struct list_head list;
-       struct nf_conntrack_tuple tuple;
+       struct hlist_node               node;
+       struct nf_conntrack_tuple       tuple;
+       union nf_inet_addr              addr;
 };
 
 struct xt_connlimit_data {
-       struct list_head iphash[256];
-       spinlock_t lock;
+       struct hlist_head       iphash[256];
+       spinlock_t              lock;
 };
 
 static u_int32_t connlimit_rnd __read_mostly;
-static bool connlimit_rnd_inited __read_mostly;
 
 static inline unsigned int connlimit_iphash(__be32 addr)
 {
@@ -100,9 +101,9 @@ static int count_them(struct net *net,
 {
        const struct nf_conntrack_tuple_hash *found;
        struct xt_connlimit_conn *conn;
-       struct xt_connlimit_conn *tmp;
+       struct hlist_node *pos, *n;
        struct nf_conn *found_ct;
-       struct list_head *hash;
+       struct hlist_head *hash;
        bool addit = true;
        int matches = 0;
 
@@ -114,7 +115,7 @@ static int count_them(struct net *net,
        rcu_read_lock();
 
        /* check the saved connections */
-       list_for_each_entry_safe(conn, tmp, hash, list) {
+       hlist_for_each_entry_safe(conn, pos, n, hash, node) {
                found    = nf_conntrack_find_get(net, NF_CT_DEFAULT_ZONE,
                                                 &conn->tuple);
                found_ct = NULL;
@@ -134,7 +135,7 @@ static int count_them(struct net *net,
 
                if (found == NULL) {
                        /* this one is gone */
-                       list_del(&conn->list);
+                       hlist_del(&conn->node);
                        kfree(conn);
                        continue;
                }
@@ -145,12 +146,12 @@ static int count_them(struct net *net,
                         * closed already -> ditch it
                         */
                        nf_ct_put(found_ct);
-                       list_del(&conn->list);
+                       hlist_del(&conn->node);
                        kfree(conn);
                        continue;
                }
 
-               if (same_source_net(addr, mask, &conn->tuple.src.u3, family))
+               if (same_source_net(addr, mask, &conn->addr, family))
                        /* same source network -> be counted! */
                        ++matches;
                nf_ct_put(found_ct);
@@ -160,11 +161,12 @@ static int count_them(struct net *net,
 
        if (addit) {
                /* save the new connection in our list */
-               conn = kzalloc(sizeof(*conn), GFP_ATOMIC);
+               conn = kmalloc(sizeof(*conn), GFP_ATOMIC);
                if (conn == NULL)
                        return -ENOMEM;
                conn->tuple = *tuple;
-               list_add(&conn->list, hash);
+               conn->addr = *addr;
+               hlist_add_head(&conn->node, hash);
                ++matches;
        }
 
@@ -172,7 +174,7 @@ static int count_them(struct net *net,
 }
 
 static bool
-connlimit_mt(const struct sk_buff *skb, const struct xt_match_param *par)
+connlimit_mt(const struct sk_buff *skb, struct xt_action_param *par)
 {
        struct net *net = dev_net(par->in ? par->in : par->out);
        const struct xt_connlimit_info *info = par->matchinfo;
@@ -185,17 +187,19 @@ connlimit_mt(const struct sk_buff *skb, const struct xt_match_param *par)
 
        ct = nf_ct_get(skb, &ctinfo);
        if (ct != NULL)
-               tuple_ptr = &ct->tuplehash[0].tuple;
+               tuple_ptr = &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple;
        else if (!nf_ct_get_tuplepr(skb, skb_network_offset(skb),
                                    par->family, &tuple))
                goto hotdrop;
 
        if (par->family == NFPROTO_IPV6) {
                const struct ipv6hdr *iph = ipv6_hdr(skb);
-               memcpy(&addr.ip6, &iph->saddr, sizeof(iph->saddr));
+               memcpy(&addr.ip6, (info->flags & XT_CONNLIMIT_DADDR) ?
+                      &iph->daddr : &iph->saddr, sizeof(addr.ip6));
        } else {
                const struct iphdr *iph = ip_hdr(skb);
-               addr.ip = iph->saddr;
+               addr.ip = (info->flags & XT_CONNLIMIT_DADDR) ?
+                         iph->daddr : iph->saddr;
        }
 
        spin_lock_bh(&info->data->lock);
@@ -203,61 +207,66 @@ connlimit_mt(const struct sk_buff *skb, const struct xt_match_param *par)
                                 &info->mask, par->family);
        spin_unlock_bh(&info->data->lock);
 
-       if (connections < 0) {
+       if (connections < 0)
                /* kmalloc failed, drop it entirely */
-               *par->hotdrop = true;
-               return false;
-       }
+               goto hotdrop;
 
-       return (connections > info->limit) ^ info->inverse;
+       return (connections > info->limit) ^
+              !!(info->flags & XT_CONNLIMIT_INVERT);
 
  hotdrop:
-       *par->hotdrop = true;
+       par->hotdrop = true;
        return false;
 }
 
-static bool connlimit_mt_check(const struct xt_mtchk_param *par)
+static int connlimit_mt_check(const struct xt_mtchk_param *par)
 {
        struct xt_connlimit_info *info = par->matchinfo;
        unsigned int i;
+       int ret;
+
+       if (unlikely(!connlimit_rnd)) {
+               u_int32_t rand;
 
-       if (unlikely(!connlimit_rnd_inited)) {
-               get_random_bytes(&connlimit_rnd, sizeof(connlimit_rnd));
-               connlimit_rnd_inited = true;
+               do {
+                       get_random_bytes(&rand, sizeof(rand));
+               } while (!rand);
+               cmpxchg(&connlimit_rnd, 0, rand);
        }
-       if (nf_ct_l3proto_try_module_get(par->family) < 0) {
-               printk(KERN_WARNING "cannot load conntrack support for "
-                      "address family %u\n", par->family);
-               return false;
+       ret = nf_ct_l3proto_try_module_get(par->family);
+       if (ret < 0) {
+               pr_info("cannot load conntrack support for "
+                       "address family %u\n", par->family);
+               return ret;
        }
 
        /* init private data */
        info->data = kmalloc(sizeof(struct xt_connlimit_data), GFP_KERNEL);
        if (info->data == NULL) {
                nf_ct_l3proto_module_put(par->family);
-               return false;
+               return -ENOMEM;
        }
 
        spin_lock_init(&info->data->lock);
        for (i = 0; i < ARRAY_SIZE(info->data->iphash); ++i)
-               INIT_LIST_HEAD(&info->data->iphash[i]);
+               INIT_HLIST_HEAD(&info->data->iphash[i]);
 
-       return true;
+       return 0;
 }
 
 static void connlimit_mt_destroy(const struct xt_mtdtor_param *par)
 {
        const struct xt_connlimit_info *info = par->matchinfo;
        struct xt_connlimit_conn *conn;
-       struct xt_connlimit_conn *tmp;
-       struct list_head *hash = info->data->iphash;
+       struct hlist_node *pos, *n;
+       struct hlist_head *hash = info->data->iphash;
        unsigned int i;
 
        nf_ct_l3proto_module_put(par->family);
 
        for (i = 0; i < ARRAY_SIZE(info->data->iphash); ++i) {
-               list_for_each_entry_safe(conn, tmp, &hash[i], list) {
-                       list_del(&conn->list);
+               hlist_for_each_entry_safe(conn, pos, n, &hash[i], node) {
+                       hlist_del(&conn->node);
                        kfree(conn);
                }
        }
@@ -265,25 +274,38 @@ static void connlimit_mt_destroy(const struct xt_mtdtor_param *par)
        kfree(info->data);
 }
 
-static struct xt_match connlimit_mt_reg __read_mostly = {
-       .name       = "connlimit",
-       .revision   = 0,
-       .family     = NFPROTO_UNSPEC,
-       .checkentry = connlimit_mt_check,
-       .match      = connlimit_mt,
-       .matchsize  = sizeof(struct xt_connlimit_info),
-       .destroy    = connlimit_mt_destroy,
-       .me         = THIS_MODULE,
+static struct xt_match connlimit_mt_reg[] __read_mostly = {
+       {
+               .name       = "connlimit",
+               .revision   = 0,
+               .family     = NFPROTO_UNSPEC,
+               .checkentry = connlimit_mt_check,
+               .match      = connlimit_mt,
+               .matchsize  = sizeof(struct xt_connlimit_info),
+               .destroy    = connlimit_mt_destroy,
+               .me         = THIS_MODULE,
+       },
+       {
+               .name       = "connlimit",
+               .revision   = 1,
+               .family     = NFPROTO_UNSPEC,
+               .checkentry = connlimit_mt_check,
+               .match      = connlimit_mt,
+               .matchsize  = sizeof(struct xt_connlimit_info),
+               .destroy    = connlimit_mt_destroy,
+               .me         = THIS_MODULE,
+       },
 };
 
 static int __init connlimit_mt_init(void)
 {
-       return xt_register_match(&connlimit_mt_reg);
+       return xt_register_matches(connlimit_mt_reg,
+              ARRAY_SIZE(connlimit_mt_reg));
 }
 
 static void __exit connlimit_mt_exit(void)
 {
-       xt_unregister_match(&connlimit_mt_reg);
+       xt_unregister_matches(connlimit_mt_reg, ARRAY_SIZE(connlimit_mt_reg));
 }
 
 module_init(connlimit_mt_init);