3 files changed, 137 insertions, 107 deletions

diff --git a/net/ipv4/netfilter/Kconfig b/net/ipv4/netfilter/Kconfig
index 30aa8e2ee214..85190de5710a 100644
--- a/net/ipv4/netfilter/Kconfig
+++ b/net/ipv4/netfilter/Kconfig
@@ -8,6 +8,7 @@ menu "IP: Netfilter Configuration"
 # connection tracking, helpers and protocols
 config IP_NF_CONNTRACK
         tristate "Connection tracking (required for masq/NAT)"
+        select NETFILTER_NETLINK if IP_NF_CONNTRACK_NETLINK!=n
         ---help---
           Connection tracking keeps a record of what packets have passed
           through your machine, in order to figure out how they are related
@@ -51,6 +52,15 @@ config IP_NF_CONNTRACK_EVENTS
           
           IF unsure, say `N'.
 
+config IP_NF_CONNTRACK_NETLINK
+        tristate 'Connection tracking netlink interface'
+        depends on IP_NF_CONNTRACK && NETFILTER_NETLINK
+        default IP_NF_CONNTRACK if NETFILTER_NETLINK=y
+        default m if NETFILTER_NETLINK=m
+        help
+          This option enables support for a netlink-based userspace interface
+
+
 config IP_NF_CT_PROTO_SCTP
         tristate  'SCTP protocol connection tracking support (EXPERIMENTAL)'
         depends on IP_NF_CONNTRACK && EXPERIMENTAL
@@ -774,11 +784,5 @@ config IP_NF_ARP_MANGLE
           Allows altering the ARP packet payload: source and destination
           hardware and network addresses.
 
-config IP_NF_CONNTRACK_NETLINK
-        tristate 'Connection tracking netlink interface'
-        depends on IP_NF_CONNTRACK && NETFILTER_NETLINK
-        help
-          This option enables support for a netlink-based userspace interface
-
 endmenu
 
diff --git a/net/ipv4/netfilter/ip_conntrack_core.c b/net/ipv4/netfilter/ip_conntrack_core.c
index 19cba16e6e1e..f8cd8e42961e 100644
--- a/net/ipv4/netfilter/ip_conntrack_core.c
+++ b/net/ipv4/netfilter/ip_conntrack_core.c
@@ -1143,7 +1143,10 @@ void ip_ct_refresh_acct(struct ip_conntrack *ct,
                 if (del_timer(&ct->timeout)) {
                         ct->timeout.expires = jiffies + extra_jiffies;
                         add_timer(&ct->timeout);
-                        ip_conntrack_event_cache(IPCT_REFRESH, skb);
+                        /* FIXME: We loose some REFRESH events if this function
+                         * is called without an skb.  I'll fix this later -HW */
+                        if (skb)
+                                ip_conntrack_event_cache(IPCT_REFRESH, skb);
                 }
                 ct_add_counters(ct, ctinfo, skb);
                 write_unlock_bh(&ip_conntrack_lock);
diff --git a/net/ipv4/netfilter/ipt_CLUSTERIP.c b/net/ipv4/netfilter/ipt_CLUSTERIP.c
index 7d38913754b1..9bcb398fbc1f 100644
--- a/net/ipv4/netfilter/ipt_CLUSTERIP.c
+++ b/net/ipv4/netfilter/ipt_CLUSTERIP.c
@@ -13,6 +13,7 @@
 #include <linux/config.h>
 #include <linux/proc_fs.h>
 #include <linux/jhash.h>
+#include <linux/bitops.h>
 #include <linux/skbuff.h>
 #include <linux/ip.h>
 #include <linux/tcp.h>
@@ -30,7 +31,7 @@
 #include <linux/netfilter_ipv4/ipt_CLUSTERIP.h>
 #include <linux/netfilter_ipv4/ip_conntrack.h>
 
-#define CLUSTERIP_VERSION "0.7"
+#define CLUSTERIP_VERSION "0.8"
 
 #define DEBUG_CLUSTERIP
 
@@ -49,13 +50,14 @@ MODULE_DESCRIPTION("iptables target for CLUSTERIP");
 struct clusterip_config {
         struct list_head list;                  /* list of all configs */
         atomic_t refcount;                      /* reference count */
+        atomic_t entries;                       /* number of entries/rules
+                                                 * referencing us */
 
         u_int32_t clusterip;                    /* the IP address */
         u_int8_t clustermac[ETH_ALEN];          /* the MAC address */
         struct net_device *dev;                 /* device */
         u_int16_t num_total_nodes;              /* total number of nodes */
-        u_int16_t num_local_nodes;              /* number of local nodes */
-        u_int16_t local_nodes[CLUSTERIP_MAX_NODES];     /* node number array */
+        unsigned long local_nodes;              /* node number array */
 
 #ifdef CONFIG_PROC_FS
         struct proc_dir_entry *pde;             /* proc dir entry */
@@ -66,8 +68,7 @@ struct clusterip_config {
 
 static LIST_HEAD(clusterip_configs);
 
-/* clusterip_lock protects the clusterip_configs list _AND_ the configurable
- * data within all structurses (num_local_nodes, local_nodes[]) */
+/* clusterip_lock protects the clusterip_configs list */
 static DEFINE_RWLOCK(clusterip_lock);
 
 #ifdef CONFIG_PROC_FS
@@ -76,23 +77,48 @@ static struct proc_dir_entry *clusterip_procdir;
 #endif
 
 static inline void
-clusterip_config_get(struct clusterip_config *c) {
+clusterip_config_get(struct clusterip_config *c)
+{
         atomic_inc(&c->refcount);
 }
 
 static inline void
-clusterip_config_put(struct clusterip_config *c) {
-        if (atomic_dec_and_test(&c->refcount)) {
+clusterip_config_put(struct clusterip_config *c)
+{
+        if (atomic_dec_and_test(&c->refcount))
+                kfree(c);
+}
+
+/* increase the count of entries(rules) using/referencing this config */
+static inline void
+clusterip_config_entry_get(struct clusterip_config *c)
+{
+        atomic_inc(&c->entries);
+}
+
+/* decrease the count of entries using/referencing this config.  If last
+ * entry(rule) is removed, remove the config from lists, but don't free it
+ * yet, since proc-files could still be holding references */
+static inline void
+clusterip_config_entry_put(struct clusterip_config *c)
+{
+        if (atomic_dec_and_test(&c->entries)) {
                 write_lock_bh(&clusterip_lock);
                 list_del(&c->list);
                 write_unlock_bh(&clusterip_lock);
+
                 dev_mc_delete(c->dev, c->clustermac, ETH_ALEN, 0);
                 dev_put(c->dev);
-                kfree(c);
+
+                /* In case anyone still accesses the file, the open/close
+                 * functions are also incrementing the refcount on their own,
+                 * so it's safe to remove the entry even if it's in use. */
+#ifdef CONFIG_PROC_FS
+                remove_proc_entry(c->pde->name, c->pde->parent);
+#endif
         }
 }
 
-
 static struct clusterip_config *
 __clusterip_config_find(u_int32_t clusterip)
 {
@@ -111,7 +137,7 @@ __clusterip_config_find(u_int32_t clusterip)
 }
 
 static inline struct clusterip_config *
-clusterip_config_find_get(u_int32_t clusterip)
+clusterip_config_find_get(u_int32_t clusterip, int entry)
 {
         struct clusterip_config *c;
 
@@ -122,11 +148,24 @@ clusterip_config_find_get(u_int32_t clusterip)
                 return NULL;
         }
         atomic_inc(&c->refcount);
+        if (entry)
+                atomic_inc(&c->entries);
         read_unlock_bh(&clusterip_lock);
 
         return c;
 }
 
+static void
+clusterip_config_init_nodelist(struct clusterip_config *c,
+                               const struct ipt_clusterip_tgt_info *i)
+{
+        int n;
+
+        for (n = 0; n < i->num_local_nodes; n++) {
+                set_bit(i->local_nodes[n] - 1, &c->local_nodes);
+        }
+}
+
 static struct clusterip_config *
 clusterip_config_init(struct ipt_clusterip_tgt_info *i, u_int32_t ip,
                         struct net_device *dev)
@@ -143,11 +182,11 @@ clusterip_config_init(struct ipt_clusterip_tgt_info *i, u_int32_t ip,
         c->clusterip = ip;
         memcpy(&c->clustermac, &i->clustermac, ETH_ALEN);
         c->num_total_nodes = i->num_total_nodes;
-        c->num_local_nodes = i->num_local_nodes;
-        memcpy(&c->local_nodes, &i->local_nodes, sizeof(c->local_nodes));
+        clusterip_config_init_nodelist(c, i);
         c->hash_mode = i->hash_mode;
         c->hash_initval = i->hash_initval;
         atomic_set(&c->refcount, 1);
+        atomic_set(&c->entries, 1);
 
 #ifdef CONFIG_PROC_FS
         /* create proc dir entry */
@@ -171,53 +210,28 @@ clusterip_config_init(struct ipt_clusterip_tgt_info *i, u_int32_t ip,
 static int
 clusterip_add_node(struct clusterip_config *c, u_int16_t nodenum)
 {
-        int i;
-
-        write_lock_bh(&clusterip_lock);
 
-        if (c->num_local_nodes >= CLUSTERIP_MAX_NODES
-            || nodenum > CLUSTERIP_MAX_NODES) {
-                write_unlock_bh(&clusterip_lock);
+        if (nodenum == 0 ||
+            nodenum > c->num_total_nodes)
                 return 1;
-        }
-
-        /* check if we alrady have this number in our array */
-        for (i = 0; i < c->num_local_nodes; i++) {
-                if (c->local_nodes[i] == nodenum) {
-                        write_unlock_bh(&clusterip_lock);
-                        return 1;
-                }
-        }
 
-        c->local_nodes[c->num_local_nodes++] = nodenum;
+        /* check if we already have this number in our bitfield */
+        if (test_and_set_bit(nodenum - 1, &c->local_nodes))
+                return 1;
 
-        write_unlock_bh(&clusterip_lock);
         return 0;
 }
 
 static int
 clusterip_del_node(struct clusterip_config *c, u_int16_t nodenum)
 {
-        int i;
-
-        write_lock_bh(&clusterip_lock);
-
-        if (c->num_local_nodes <= 1 || nodenum > CLUSTERIP_MAX_NODES) {
-                write_unlock_bh(&clusterip_lock);
+        if (nodenum == 0 ||
+            nodenum > c->num_total_nodes)
                 return 1;
-        }
                 
-        for (i = 0; i < c->num_local_nodes; i++) {
-                if (c->local_nodes[i] == nodenum) {
-                        int size = sizeof(u_int16_t)*(c->num_local_nodes-(i+1));
-                        memmove(&c->local_nodes[i], &c->local_nodes[i+1], size);
-                        c->num_local_nodes--;
-                        write_unlock_bh(&clusterip_lock);
-                        return 0;
-                }
-        }
+        if (test_and_clear_bit(nodenum - 1, &c->local_nodes))
+                return 0;
 
-        write_unlock_bh(&clusterip_lock);
         return 1;
 }
 
@@ -285,25 +299,7 @@ clusterip_hashfn(struct sk_buff *skb, struct clusterip_config *config)
 static inline int
 clusterip_responsible(struct clusterip_config *config, u_int32_t hash)
 {
-        int i;
-
-        read_lock_bh(&clusterip_lock);
-
-        if (config->num_local_nodes == 0) {
-                read_unlock_bh(&clusterip_lock);
-                return 0;
-        }
-
-        for (i = 0; i < config->num_local_nodes; i++) {
-                if (config->local_nodes[i] == hash) {
-                        read_unlock_bh(&clusterip_lock);
-                        return 1;
-                }
-        }
-
-        read_unlock_bh(&clusterip_lock);
-
-        return 0;
+        return test_bit(hash - 1, &config->local_nodes);
 }
 
 /*********************************************************************** 
@@ -415,8 +411,26 @@ checkentry(const char *tablename,
 
         /* FIXME: further sanity checks */
 
-        config = clusterip_config_find_get(e->ip.dst.s_addr);
-        if (!config) {
+        config = clusterip_config_find_get(e->ip.dst.s_addr, 1);
+        if (config) {
+                if (cipinfo->config != NULL) {
+                        /* Case A: This is an entry that gets reloaded, since
+                         * it still has a cipinfo->config pointer. Simply
+                         * increase the entry refcount and return */
+                        if (cipinfo->config != config) {
+                                printk(KERN_ERR "CLUSTERIP: Reloaded entry "
+                                       "has invalid config pointer!\n");
+                                return 0;
+                        }
+                        clusterip_config_entry_get(cipinfo->config);
+                } else {
+                        /* Case B: This is a new rule referring to an existing
+                         * clusterip config. */
+                        cipinfo->config = config;
+                        clusterip_config_entry_get(cipinfo->config);
+                }
+        } else {
+                /* Case C: This is a completely new clusterip config */
                 if (!(cipinfo->flags & CLUSTERIP_FLAG_NEW)) {
                         printk(KERN_WARNING "CLUSTERIP: no config found for %u.%u.%u.%u, need 'new'\n", NIPQUAD(e->ip.dst.s_addr));
                         return 0;
@@ -443,10 +457,9 @@ checkentry(const char *tablename,
                         }
                         dev_mc_add(config->dev,config->clustermac, ETH_ALEN, 0);
                 }
+                cipinfo->config = config;
         }
 
-        cipinfo->config = config;
-
         return 1;
 }
 
@@ -455,13 +468,10 @@ static void destroy(void *matchinfo, unsigned int matchinfosize)
 {
         struct ipt_clusterip_tgt_info *cipinfo = matchinfo;
 
-        /* we first remove the proc entry and then drop the reference
-         * count.  In case anyone still accesses the file, the open/close
-         * functions are also incrementing the refcount on their own */
-#ifdef CONFIG_PROC_FS
-        remove_proc_entry(cipinfo->config->pde->name,
-                          cipinfo->config->pde->parent);
-#endif
+        /* if no more entries are referencing the config, remove it
+         * from the list and destroy the proc entry */
+        clusterip_config_entry_put(cipinfo->config);
+
         clusterip_config_put(cipinfo->config);
 }
 
@@ -533,7 +543,7 @@ arp_mangle(unsigned int hook,
 
         /* if there is no clusterip configuration for the arp reply's 
          * source ip, we don't want to mangle it */
-        c = clusterip_config_find_get(payload->src_ip);
+        c = clusterip_config_find_get(payload->src_ip, 0);
         if (!c)
                 return NF_ACCEPT;
 
@@ -574,56 +584,69 @@ static struct nf_hook_ops cip_arp_ops = {
 
 #ifdef CONFIG_PROC_FS
 
+struct clusterip_seq_position {
+        unsigned int pos;       /* position */
+        unsigned int weight;    /* number of bits set == size */
+        unsigned int bit;       /* current bit */
+        unsigned long val;      /* current value */
+};
+
 static void *clusterip_seq_start(struct seq_file *s, loff_t *pos)
 {
         struct proc_dir_entry *pde = s->private;
         struct clusterip_config *c = pde->data;
-        unsigned int *nodeidx;
-
-        read_lock_bh(&clusterip_lock);
-        if (*pos >= c->num_local_nodes)
+        unsigned int weight;
+        u_int32_t local_nodes;
+        struct clusterip_seq_position *idx;
+
+        /* FIXME: possible race */
+        local_nodes = c->local_nodes;
+        weight = hweight32(local_nodes);
+        if (*pos >= weight)
                 return NULL;
 
-        nodeidx = kmalloc(sizeof(unsigned int), GFP_KERNEL);
-        if (!nodeidx)
+        idx = kmalloc(sizeof(struct clusterip_seq_position), GFP_KERNEL);
+        if (!idx)
                 return ERR_PTR(-ENOMEM);
 
-        *nodeidx = *pos;
-        return nodeidx;
+        idx->pos = *pos;
+        idx->weight = weight;
+        idx->bit = ffs(local_nodes);
+        idx->val = local_nodes;
+        clear_bit(idx->bit - 1, &idx->val);
+
+        return idx;
 }
 
 static void *clusterip_seq_next(struct seq_file *s, void *v, loff_t *pos)
 {
-        struct proc_dir_entry *pde = s->private;
-        struct clusterip_config *c = pde->data;
-        unsigned int *nodeidx = (unsigned int *)v;
+        struct clusterip_seq_position *idx = (struct clusterip_seq_position *)v;
 
-        *pos = ++(*nodeidx);
-        if (*pos >= c->num_local_nodes) {
+        *pos = ++idx->pos;
+        if (*pos >= idx->weight) {
                 kfree(v);
                 return NULL;
         }
-        return nodeidx;
+        idx->bit = ffs(idx->val);
+        clear_bit(idx->bit - 1, &idx->val);
+        return idx;
 }
 
 static void clusterip_seq_stop(struct seq_file *s, void *v)
 {
         kfree(v);
-
-        read_unlock_bh(&clusterip_lock);
 }
 
 static int clusterip_seq_show(struct seq_file *s, void *v)
 {
-        struct proc_dir_entry *pde = s->private;
-        struct clusterip_config *c = pde->data;
-        unsigned int *nodeidx = (unsigned int *)v;
+        struct clusterip_seq_position *idx = (struct clusterip_seq_position *)v;
 
-        if (*nodeidx != 0) 
+        if (idx->pos != 0) 
                 seq_putc(s, ',');
-        seq_printf(s, "%u", c->local_nodes[*nodeidx]);
 
-        if (*nodeidx == c->num_local_nodes-1)
+        seq_printf(s, "%u", idx->bit);
+
+        if (idx->pos == idx->weight - 1)
                 seq_putc(s, '\n');
 
         return 0;