netfilter: ebt_log: add net namespace support for ebt_log

Add pernet support to ebt_log by means of the new nf_log_set
function added in (30e0c6a netfilter: nf_log: prepare net
namespace support for loggers).

Since syslog ns has yet not been implemented, we don't want
the containers to DDOS host's syslogd. So only enable ebt_log
only from init_net and wait for syslog ns support.

Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

1 files changed, 35 insertions, 2 deletions

diff --git a/net/bridge/netfilter/ebt_log.c b/net/bridge/netfilter/ebt_log.c
index 08e5ea5ec4ed..9878eb8204c5 100644
--- a/net/bridge/netfilter/ebt_log.c
+++ b/net/bridge/netfilter/ebt_log.c
@@ -78,6 +78,11 @@ ebt_log_packet(u_int8_t pf, unsigned int hooknum,
    const char *prefix)
 {
         unsigned int bitmask;
+        struct net *net = dev_net(in ? in : out);
+
+        /* FIXME: Disabled from containers until syslog ns is supported */
+        if (!net_eq(net, &init_net))
+                return;
 
         spin_lock_bh(&ebt_log_lock);
         printk(KERN_SOH "%c%s IN=%s OUT=%s MAC source = %pM MAC dest = %pM proto = 0x%04x",
@@ -207,19 +212,47 @@ static struct nf_logger ebt_log_logger __read_mostly = {
         .me             = THIS_MODULE,
 };
 
+static int __net_init ebt_log_net_init(struct net *net)
+{
+        nf_log_set(net, NFPROTO_BRIDGE, &ebt_log_logger);
+        return 0;
+}
+
+static void __net_exit ebt_log_net_fini(struct net *net)
+{
+        nf_log_unset(net, &ebt_log_logger);
+}
+
+static struct pernet_operations ebt_log_net_ops = {
+        .init = ebt_log_net_init,
+        .exit = ebt_log_net_fini,
+};
+
 static int __init ebt_log_init(void)
 {
         int ret;
 
+        ret = register_pernet_subsys(&ebt_log_net_ops);
+        if (ret < 0)
+                goto err_pernet;
+
         ret = xt_register_target(&ebt_log_tg_reg);
         if (ret < 0)
-                return ret;
+                goto err_target;
+
         nf_log_register(NFPROTO_BRIDGE, &ebt_log_logger);
-        return 0;
+
+        return ret;
+
+err_target:
+        unregister_pernet_subsys(&ebt_log_net_ops);
+err_pernet:
+        return ret;
 }
 
 static void __exit ebt_log_fini(void)
 {
+        unregister_pernet_subsys(&ebt_log_net_ops);
         nf_log_unregister(&ebt_log_logger);
         xt_unregister_target(&ebt_log_tg_reg);
 }