netfilter: use a linked list of loggers

[mv-sheeva.git] / net / netfilter / nf_log.c

diff --git a/net/netfilter/nf_log.c b/net/netfilter/nf_log.c
index fa8ae5d2659c6ad1fb13b7dbb20743d0cc1a8886..a228b5fbcf7c60ba8967031f7fc9dd255d2b5016 100644 (file)
--- a/net/netfilter/nf_log.c
+++ b/net/netfilter/nf_log.c
@@ -16,56 +16,60 @@
 #define NF_LOG_PREFIXLEN               128
 
 static const struct nf_logger *nf_loggers[NFPROTO_NUMPROTO] __read_mostly;
+static struct list_head nf_loggers_l[NFPROTO_NUMPROTO] __read_mostly;
 static DEFINE_MUTEX(nf_log_mutex);
 
-/* return EBUSY if somebody else is registered, EEXIST if the same logger
- * is registred, 0 on success. */
-int nf_log_register(u_int8_t pf, const struct nf_logger *logger)
+static struct nf_logger *__find_logger(int pf, const char *str_logger)
 {
-       int ret;
+       struct nf_logger *t;
 
-       if (pf >= ARRAY_SIZE(nf_loggers))
-               return -EINVAL;
-
-       /* Any setup of logging members must be done before
-        * substituting pointer. */
-       ret = mutex_lock_interruptible(&nf_log_mutex);
-       if (ret < 0)
-               return ret;
-
-       if (!nf_loggers[pf])
-               rcu_assign_pointer(nf_loggers[pf], logger);
-       else if (nf_loggers[pf] == logger)
-               ret = -EEXIST;
-       else
-               ret = -EBUSY;
+       list_for_each_entry(t, &nf_loggers_l[pf], list[pf]) {
+               if (!strnicmp(str_logger, t->name, strlen(t->name)))
+                       return t;
+       }
 
-       mutex_unlock(&nf_log_mutex);
-       return ret;
+       return NULL;
 }
-EXPORT_SYMBOL(nf_log_register);
 
-void nf_log_unregister_pf(u_int8_t pf)
+/* return EEXIST if the same logger is registred, 0 on success. */
+int nf_log_register(u_int8_t pf, struct nf_logger *logger)
 {
+       const struct nf_logger *llog;
+
        if (pf >= ARRAY_SIZE(nf_loggers))
-               return;
+               return -EINVAL;
+
        mutex_lock(&nf_log_mutex);
-       rcu_assign_pointer(nf_loggers[pf], NULL);
+
+       if (pf == NFPROTO_UNSPEC) {
+               int i;
+               for (i = NFPROTO_UNSPEC; i < NFPROTO_NUMPROTO; i++)
+                       list_add_tail(&(logger->list[i]), &(nf_loggers_l[i]));
+       } else {
+               /* register at end of list to honor first register win */
+               list_add_tail(&logger->list[pf], &nf_loggers_l[pf]);
+               llog = rcu_dereference(nf_loggers[pf]);
+               if (llog == NULL)
+                       rcu_assign_pointer(nf_loggers[pf], logger);
+       }
+
        mutex_unlock(&nf_log_mutex);
 
-       /* Give time to concurrent readers. */
-       synchronize_rcu();
+       return 0;
 }
-EXPORT_SYMBOL(nf_log_unregister_pf);
+EXPORT_SYMBOL(nf_log_register);
 
-void nf_log_unregister(const struct nf_logger *logger)
+void nf_log_unregister(struct nf_logger *logger)
 {
+       const struct nf_logger *c_logger;
        int i;
 
        mutex_lock(&nf_log_mutex);
        for (i = 0; i < ARRAY_SIZE(nf_loggers); i++) {
-               if (nf_loggers[i] == logger)
+               c_logger = rcu_dereference(nf_loggers[i]);
+               if (c_logger == logger)
                        rcu_assign_pointer(nf_loggers[i], NULL);
+               list_del(&logger->list[i]);
        }
        mutex_unlock(&nf_log_mutex);
 
@@ -73,6 +77,27 @@ void nf_log_unregister(const struct nf_logger *logger)
 }
 EXPORT_SYMBOL(nf_log_unregister);
 
+int nf_log_bind_pf(u_int8_t pf, const struct nf_logger *logger)
+{
+       mutex_lock(&nf_log_mutex);
+       if (__find_logger(pf, logger->name) == NULL) {
+               mutex_unlock(&nf_log_mutex);
+               return -ENOENT;
+       }
+       rcu_assign_pointer(nf_loggers[pf], logger);
+       mutex_unlock(&nf_log_mutex);
+       return 0;
+}
+EXPORT_SYMBOL(nf_log_bind_pf);
+
+void nf_log_unbind_pf(u_int8_t pf)
+{
+       mutex_lock(&nf_log_mutex);
+       rcu_assign_pointer(nf_loggers[pf], NULL);
+       mutex_unlock(&nf_log_mutex);
+}
+EXPORT_SYMBOL(nf_log_unbind_pf);
+
 void nf_log_packet(u_int8_t pf,
                   unsigned int hooknum,
                   const struct sk_buff *skb,
@@ -163,10 +188,15 @@ static const struct file_operations nflog_file_ops = {
 
 int __init netfilter_log_init(void)
 {
+       int i;
 #ifdef CONFIG_PROC_FS
        if (!proc_create("nf_log", S_IRUGO,
                         proc_net_netfilter, &nflog_file_ops))
                return -1;
 #endif
+
+       for (i = NFPROTO_UNSPEC; i < NFPROTO_NUMPROTO; i++)
+               INIT_LIST_HEAD(&(nf_loggers_l[i]));
+
        return 0;
 }