1 files changed, 95 insertions, 37 deletions

diff --git a/net/ipv4/netfilter/ip_conntrack_core.c b/net/ipv4/netfilter/ip_conntrack_core.c
index 07a80b56e8dc..422ab68ee7fb 100644
--- a/net/ipv4/netfilter/ip_conntrack_core.c
+++ b/net/ipv4/netfilter/ip_conntrack_core.c
@@ -50,7 +50,7 @@
 #include <linux/netfilter_ipv4/ip_conntrack_core.h>
 #include <linux/netfilter_ipv4/listhelp.h>
 
-#define IP_CONNTRACK_VERSION    "2.3"
+#define IP_CONNTRACK_VERSION    "2.4"
 
 #if 0
 #define DEBUGP printk
@@ -148,16 +148,20 @@ DEFINE_PER_CPU(struct ip_conntrack_stat, ip_conntrack_stat);
 static int ip_conntrack_hash_rnd_initted;
 static unsigned int ip_conntrack_hash_rnd;
 
-static u_int32_t
-hash_conntrack(const struct ip_conntrack_tuple *tuple)
+static u_int32_t __hash_conntrack(const struct ip_conntrack_tuple *tuple,
+                            unsigned int size, unsigned int rnd)
 {
-#if 0
-        dump_tuple(tuple);
-#endif
         return (jhash_3words(tuple->src.ip,
                              (tuple->dst.ip ^ tuple->dst.protonum),
                              (tuple->src.u.all | (tuple->dst.u.all << 16)),
-                             ip_conntrack_hash_rnd) % ip_conntrack_htable_size);
+                             rnd) % size);
+}
+
+static u_int32_t
+hash_conntrack(const struct ip_conntrack_tuple *tuple)
+{
+        return __hash_conntrack(tuple, ip_conntrack_htable_size,
+                                ip_conntrack_hash_rnd);
 }
 
 int
@@ -1341,14 +1345,13 @@ static int kill_all(struct ip_conntrack *i, void *data)
         return 1;
 }
 
-static void free_conntrack_hash(void)
+static void free_conntrack_hash(struct list_head *hash, int vmalloced,int size)
 {
-        if (ip_conntrack_vmalloc)
-                vfree(ip_conntrack_hash);
+        if (vmalloced)
+                vfree(hash);
         else
-                free_pages((unsigned long)ip_conntrack_hash, 
-                           get_order(sizeof(struct list_head)
-                                     * ip_conntrack_htable_size));
+                free_pages((unsigned long)hash, 
+                           get_order(sizeof(struct list_head) * size));
 }
 
 void ip_conntrack_flush()
@@ -1378,12 +1381,83 @@ void ip_conntrack_cleanup(void)
         ip_conntrack_flush();
         kmem_cache_destroy(ip_conntrack_cachep);
         kmem_cache_destroy(ip_conntrack_expect_cachep);
-        free_conntrack_hash();
+        free_conntrack_hash(ip_conntrack_hash, ip_conntrack_vmalloc,
+                            ip_conntrack_htable_size);
         nf_unregister_sockopt(&so_getorigdst);
 }
 
-static int hashsize;
-module_param(hashsize, int, 0400);
+static struct list_head *alloc_hashtable(int size, int *vmalloced)
+{
+        struct list_head *hash;
+        unsigned int i;
+
+        *vmalloced = 0; 
+        hash = (void*)__get_free_pages(GFP_KERNEL, 
+                                       get_order(sizeof(struct list_head)
+                                                 * size));
+        if (!hash) { 
+                *vmalloced = 1;
+                printk(KERN_WARNING"ip_conntrack: falling back to vmalloc.\n");
+                hash = vmalloc(sizeof(struct list_head) * size);
+        }
+
+        if (hash)
+                for (i = 0; i < size; i++)
+                        INIT_LIST_HEAD(&hash[i]);
+
+        return hash;
+}
+
+int set_hashsize(const char *val, struct kernel_param *kp)
+{
+        int i, bucket, hashsize, vmalloced;
+        int old_vmalloced, old_size;
+        int rnd;
+        struct list_head *hash, *old_hash;
+        struct ip_conntrack_tuple_hash *h;
+
+        /* On boot, we can set this without any fancy locking. */
+        if (!ip_conntrack_htable_size)
+                return param_set_int(val, kp);
+
+        hashsize = simple_strtol(val, NULL, 0);
+        if (!hashsize)
+                return -EINVAL;
+
+        hash = alloc_hashtable(hashsize, &vmalloced);
+        if (!hash)
+                return -ENOMEM;
+
+        /* We have to rehash for the new table anyway, so we also can 
+         * use a new random seed */
+        get_random_bytes(&rnd, 4);
+
+        write_lock_bh(&ip_conntrack_lock);
+        for (i = 0; i < ip_conntrack_htable_size; i++) {
+                while (!list_empty(&ip_conntrack_hash[i])) {
+                        h = list_entry(ip_conntrack_hash[i].next,
+                                       struct ip_conntrack_tuple_hash, list);
+                        list_del(&h->list);
+                        bucket = __hash_conntrack(&h->tuple, hashsize, rnd);
+                        list_add_tail(&h->list, &hash[bucket]);
+                }
+        }
+        old_size = ip_conntrack_htable_size;
+        old_vmalloced = ip_conntrack_vmalloc;
+        old_hash = ip_conntrack_hash;
+
+        ip_conntrack_htable_size = hashsize;
+        ip_conntrack_vmalloc = vmalloced;
+        ip_conntrack_hash = hash;
+        ip_conntrack_hash_rnd = rnd;
+        write_unlock_bh(&ip_conntrack_lock);
+
+        free_conntrack_hash(old_hash, old_vmalloced, old_size);
+        return 0;
+}
+
+module_param_call(hashsize, set_hashsize, param_get_uint,
+                  &ip_conntrack_htable_size, 0600);
 
 int __init ip_conntrack_init(void)
 {
@@ -1392,9 +1466,7 @@ int __init ip_conntrack_init(void)
 
         /* Idea from tcp.c: use 1/16384 of memory.  On i386: 32MB
          * machine has 256 buckets.  >= 1GB machines have 8192 buckets. */
-        if (hashsize) {
-                ip_conntrack_htable_size = hashsize;
-        } else {
+        if (!ip_conntrack_htable_size) {
                 ip_conntrack_htable_size
                         = (((num_physpages << PAGE_SHIFT) / 16384)
                            / sizeof(struct list_head));
@@ -1416,20 +1488,8 @@ int __init ip_conntrack_init(void)
                 return ret;
         }
 
-        /* AK: the hash table is twice as big than needed because it
-           uses list_head.  it would be much nicer to caches to use a
-           single pointer list head here. */
-        ip_conntrack_vmalloc = 0; 
-        ip_conntrack_hash 
-                =(void*)__get_free_pages(GFP_KERNEL, 
-                                         get_order(sizeof(struct list_head)
-                                                   *ip_conntrack_htable_size));
-        if (!ip_conntrack_hash) { 
-                ip_conntrack_vmalloc = 1;
-                printk(KERN_WARNING "ip_conntrack: falling back to vmalloc.\n");
-                ip_conntrack_hash = vmalloc(sizeof(struct list_head)
-                                            * ip_conntrack_htable_size);
-        }
+        ip_conntrack_hash = alloc_hashtable(ip_conntrack_htable_size,
+                                            &ip_conntrack_vmalloc);
         if (!ip_conntrack_hash) {
                 printk(KERN_ERR "Unable to create ip_conntrack_hash\n");
                 goto err_unreg_sockopt;
@@ -1461,9 +1521,6 @@ int __init ip_conntrack_init(void)
         ip_ct_protos[IPPROTO_ICMP] = &ip_conntrack_protocol_icmp;
         write_unlock_bh(&ip_conntrack_lock);
 
-        for (i = 0; i < ip_conntrack_htable_size; i++)
-                INIT_LIST_HEAD(&ip_conntrack_hash[i]);
-
         /* For use by ipt_REJECT */
         ip_ct_attach = ip_conntrack_attach;
 
@@ -1478,7 +1535,8 @@ int __init ip_conntrack_init(void)
 err_free_conntrack_slab:
         kmem_cache_destroy(ip_conntrack_cachep);
 err_free_hash:
-        free_conntrack_hash();
+        free_conntrack_hash(ip_conntrack_hash, ip_conntrack_vmalloc,
+                            ip_conntrack_htable_size);
 err_unreg_sockopt:
         nf_unregister_sockopt(&so_getorigdst);