netfilter: use a linked list of loggers

This patch modifies nf_log to use a linked list of loggers for each
protocol. This list of loggers is read and write protected with a
mutex.

This patch separates registration and binding. To be used as
logging module, a module has to register calling nf_log_register()
and to bind to a protocol it has to call nf_log_bind_pf().
This patch also converts the logging modules to the new API. For nfnetlink_log,
it simply switchs call to register functions to call to bind function and
adds a call to nf_log_register() during init. For other modules, it just
remove a const flag from the logger structure and replace it with a
__read_mostly.

Signed-off-by: Eric Leblond <eric@inl.fr>
Signed-off-by: Patrick McHardy <kaber@trash.net>

1 files changed, 13 insertions, 5 deletions

diff --git a/net/netfilter/nfnetlink_log.c b/net/netfilter/nfnetlink_log.c
index fa49dc7fe10..3eae3fca29d 100644
--- a/net/netfilter/nfnetlink_log.c
+++ b/net/netfilter/nfnetlink_log.c
@@ -691,7 +691,7 @@ nfulnl_recv_unsupp(struct sock *ctnl, struct sk_buff *skb,
 	return -ENOTSUPP;
 }
 
-static const struct nf_logger nfulnl_logger = {
+static struct nf_logger nfulnl_logger __read_mostly = {
 	.name	= "nfnetlink_log",
 	.logfn	= &nfulnl_log_packet,
 	.me	= THIS_MODULE,
@@ -723,9 +723,9 @@ nfulnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
 		/* Commands without queue context */
 		switch (cmd->command) {
 		case NFULNL_CFG_CMD_PF_BIND:
-			return nf_log_register(pf, &nfulnl_logger);
+			return nf_log_bind_pf(pf, &nfulnl_logger);
 		case NFULNL_CFG_CMD_PF_UNBIND:
-			nf_log_unregister_pf(pf);
+			nf_log_unbind_pf(pf);
 			return 0;
 		}
 	}
@@ -950,17 +950,25 @@ static int __init nfnetlink_log_init(void)
 		goto cleanup_netlink_notifier;
 	}
 
+	status = nf_log_register(NFPROTO_UNSPEC, &nfulnl_logger);
+	if (status < 0) {
+		printk(KERN_ERR "log: failed to register logger\n");
+		goto cleanup_subsys;
+	}
+
 #ifdef CONFIG_PROC_FS
 	if (!proc_create("nfnetlink_log", 0440,
 			 proc_net_netfilter, &nful_file_ops))
-		goto cleanup_subsys;
+		goto cleanup_logger;
 #endif
 	return status;
 
 #ifdef CONFIG_PROC_FS
+cleanup_logger:
+	nf_log_unregister(&nfulnl_logger);
+#endif
 cleanup_subsys:
 	nfnetlink_subsys_unregister(&nfulnl_subsys);
-#endif
 cleanup_netlink_notifier:
 	netlink_unregister_notifier(&nfulnl_rtnl_notifier);
 	return status;