1 files changed, 62 insertions, 18 deletions

diff --git a/net/ipv4/netfilter/ipt_CLUSTERIP.c b/net/ipv4/netfilter/ipt_CLUSTERIP.c
index 7d38913754b1..adbf4d752d0f 100644
--- a/net/ipv4/netfilter/ipt_CLUSTERIP.c
+++ b/net/ipv4/netfilter/ipt_CLUSTERIP.c
@@ -49,6 +49,8 @@ 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 */
@@ -76,23 +78,48 @@ 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 +138,7 @@ __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;
 
@@ -122,6 +149,8 @@ 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;
@@ -148,6 +177,7 @@ clusterip_config_init(struct ipt_clusterip_tgt_info *i, u_int32_t ip,
         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 */
@@ -415,8 +445,26 @@ 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 +491,9 @@ checkentry(const char *tablename,
                         }
                         dev_mc_add(config->dev,config->clustermac, ETH_ALEN, 0);
                 }
+                cipinfo->config = config;
         }
 
-        cipinfo->config = config;
-
         return 1;
 }
 
@@ -455,13 +502,10 @@ 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 +577,7 @@ 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;