netfilter: nfnetlink: netns support

Make nfnl socket per-petns.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>

6 files changed, 58 insertions, 35 deletions

diff --git a/include/linux/netfilter/nfnetlink.h b/include/linux/netfilter/nfnetlink.h
index 49d321f3ccd2..53923868c9bd 100644
--- a/include/linux/netfilter/nfnetlink.h
+++ b/include/linux/netfilter/nfnetlink.h
@@ -73,11 +73,11 @@ struct nfnetlink_subsystem {
 extern int nfnetlink_subsys_register(const struct nfnetlink_subsystem *n);
 extern int nfnetlink_subsys_unregister(const struct nfnetlink_subsystem *n);
 
-extern int nfnetlink_has_listeners(unsigned int group);
-extern int nfnetlink_send(struct sk_buff *skb, u32 pid, unsigned group, 
+extern int nfnetlink_has_listeners(struct net *net, unsigned int group);
+extern int nfnetlink_send(struct sk_buff *skb, struct net *net, u32 pid, unsigned group,
                           int echo, gfp_t flags);
-extern void nfnetlink_set_err(u32 pid, u32 group, int error);
-extern int nfnetlink_unicast(struct sk_buff *skb, u_int32_t pid, int flags);
+extern void nfnetlink_set_err(struct net *net, u32 pid, u32 group, int error);
+extern int nfnetlink_unicast(struct sk_buff *skb, struct net *net, u_int32_t pid, int flags);
 
 extern void nfnl_lock(void);
 extern void nfnl_unlock(void);
diff --git a/include/net/net_namespace.h b/include/net/net_namespace.h
index f307e133d14c..82b7be4db89a 100644
--- a/include/net/net_namespace.h
+++ b/include/net/net_namespace.h
@@ -81,6 +81,8 @@ struct net {
 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
         struct netns_ct         ct;
 #endif
+        struct sock             *nfnl;
+        struct sock             *nfnl_stash;
 #endif
 #ifdef CONFIG_XFRM
         struct netns_xfrm       xfrm;
diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c
index 59d8064eb522..d4c5d06677f9 100644
--- a/net/netfilter/nf_conntrack_netlink.c
+++ b/net/netfilter/nf_conntrack_netlink.c
@@ -482,7 +482,7 @@ ctnetlink_conntrack_event(unsigned int events, struct nf_ct_event *item)
         } else
                 return 0;
 
-        if (!item->report && !nfnetlink_has_listeners(group))
+        if (!item->report && !nfnetlink_has_listeners(&init_net, group))
                 return 0;
 
         skb = nlmsg_new(ctnetlink_nlmsg_size(ct), GFP_ATOMIC);
@@ -559,7 +559,8 @@ ctnetlink_conntrack_event(unsigned int events, struct nf_ct_event *item)
         rcu_read_unlock();
 
         nlmsg_end(skb, nlh);
-        err = nfnetlink_send(skb, item->pid, group, item->report, GFP_ATOMIC);
+        err = nfnetlink_send(skb, &init_net, item->pid, group, item->report,
+                             GFP_ATOMIC);
         if (err == -ENOBUFS || err == -EAGAIN)
                 return -ENOBUFS;
 
@@ -571,7 +572,7 @@ nla_put_failure:
 nlmsg_failure:
         kfree_skb(skb);
 errout:
-        nfnetlink_set_err(0, group, -ENOBUFS);
+        nfnetlink_set_err(&init_net, 0, group, -ENOBUFS);
         return 0;
 }
 #endif /* CONFIG_NF_CONNTRACK_EVENTS */
@@ -1539,7 +1540,7 @@ ctnetlink_expect_event(unsigned int events, struct nf_exp_event *item)
                 return 0;
 
         if (!item->report &&
-            !nfnetlink_has_listeners(NFNLGRP_CONNTRACK_EXP_NEW))
+            !nfnetlink_has_listeners(&init_net, NFNLGRP_CONNTRACK_EXP_NEW))
                 return 0;
 
         skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
@@ -1562,7 +1563,7 @@ ctnetlink_expect_event(unsigned int events, struct nf_exp_event *item)
         rcu_read_unlock();
 
         nlmsg_end(skb, nlh);
-        nfnetlink_send(skb, item->pid, NFNLGRP_CONNTRACK_EXP_NEW,
+        nfnetlink_send(skb, &init_net, item->pid, NFNLGRP_CONNTRACK_EXP_NEW,
                        item->report, GFP_ATOMIC);
         return 0;
 
@@ -1572,7 +1573,7 @@ nla_put_failure:
 nlmsg_failure:
         kfree_skb(skb);
 errout:
-        nfnetlink_set_err(0, 0, -ENOBUFS);
+        nfnetlink_set_err(&init_net, 0, 0, -ENOBUFS);
         return 0;
 }
 #endif
diff --git a/net/netfilter/nfnetlink.c b/net/netfilter/nfnetlink.c
index eedc0c1ac7a4..8eb0cc23ada3 100644
--- a/net/netfilter/nfnetlink.c
+++ b/net/netfilter/nfnetlink.c
@@ -40,7 +40,6 @@ MODULE_ALIAS_NET_PF_PROTO(PF_NETLINK, NETLINK_NETFILTER);
 
 static char __initdata nfversion[] = "0.30";
 
-static struct sock *nfnl = NULL;
 static const struct nfnetlink_subsystem *subsys_table[NFNL_SUBSYS_COUNT];
 static DEFINE_MUTEX(nfnl_mutex);
 
@@ -101,34 +100,35 @@ nfnetlink_find_client(u_int16_t type, const struct nfnetlink_subsystem *ss)
         return &ss->cb[cb_id];
 }
 
-int nfnetlink_has_listeners(unsigned int group)
+int nfnetlink_has_listeners(struct net *net, unsigned int group)
 {
-        return netlink_has_listeners(nfnl, group);
+        return netlink_has_listeners(net->nfnl, group);
 }
 EXPORT_SYMBOL_GPL(nfnetlink_has_listeners);
 
-int nfnetlink_send(struct sk_buff *skb, u32 pid,
+int nfnetlink_send(struct sk_buff *skb, struct net *net, u32 pid,
                    unsigned group, int echo, gfp_t flags)
 {
-        return nlmsg_notify(nfnl, skb, pid, group, echo, flags);
+        return nlmsg_notify(net->nfnl, skb, pid, group, echo, flags);
 }
 EXPORT_SYMBOL_GPL(nfnetlink_send);
 
-void nfnetlink_set_err(u32 pid, u32 group, int error)
+void nfnetlink_set_err(struct net *net, u32 pid, u32 group, int error)
 {
-        netlink_set_err(nfnl, pid, group, error);
+        netlink_set_err(net->nfnl, pid, group, error);
 }
 EXPORT_SYMBOL_GPL(nfnetlink_set_err);
 
-int nfnetlink_unicast(struct sk_buff *skb, u_int32_t pid, int flags)
+int nfnetlink_unicast(struct sk_buff *skb, struct net *net, u_int32_t pid, int flags)
 {
-        return netlink_unicast(nfnl, skb, pid, flags);
+        return netlink_unicast(net->nfnl, skb, pid, flags);
 }
 EXPORT_SYMBOL_GPL(nfnetlink_unicast);
 
 /* Process one complete nfnetlink message. */
 static int nfnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 {
+        struct net *net = sock_net(skb->sk);
         const struct nfnl_callback *nc;
         const struct nfnetlink_subsystem *ss;
         int type, err;
@@ -170,7 +170,7 @@ replay:
                 if (err < 0)
                         return err;
 
-                err = nc->call(nfnl, skb, nlh, (const struct nlattr **)cda);
+                err = nc->call(net->nfnl, skb, nlh, (const struct nlattr **)cda);
                 if (err == -EAGAIN)
                         goto replay;
                 return err;
@@ -184,26 +184,45 @@ static void nfnetlink_rcv(struct sk_buff *skb)
         nfnl_unlock();
 }
 
-static void __exit nfnetlink_exit(void)
+static int __net_init nfnetlink_net_init(struct net *net)
 {
-        printk("Removing netfilter NETLINK layer.\n");
-        netlink_kernel_release(nfnl);
-        return;
+        struct sock *nfnl;
+
+        nfnl = netlink_kernel_create(net, NETLINK_NETFILTER, NFNLGRP_MAX,
+                                     nfnetlink_rcv, NULL, THIS_MODULE);
+        if (!nfnl)
+                return -ENOMEM;
+        net->nfnl_stash = nfnl;
+        rcu_assign_pointer(net->nfnl, nfnl);
+        return 0;
 }
 
-static int __init nfnetlink_init(void)
+static void __net_exit nfnetlink_net_exit_batch(struct list_head *net_exit_list)
 {
-        printk("Netfilter messages via NETLINK v%s.\n", nfversion);
+        struct net *net;
 
-        nfnl = netlink_kernel_create(&init_net, NETLINK_NETFILTER, NFNLGRP_MAX,
-                                     nfnetlink_rcv, NULL, THIS_MODULE);
-        if (!nfnl) {
-                printk(KERN_ERR "cannot initialize nfnetlink!\n");
-                return -ENOMEM;
-        }
+        list_for_each_entry(net, net_exit_list, exit_list)
+                rcu_assign_pointer(net->nfnl, NULL);
+        synchronize_net();
+        list_for_each_entry(net, net_exit_list, exit_list)
+                netlink_kernel_release(net->nfnl_stash);
+}
 
-        return 0;
+static struct pernet_operations nfnetlink_net_ops = {
+        .init           = nfnetlink_net_init,
+        .exit_batch     = nfnetlink_net_exit_batch,
+};
+
+static int __init nfnetlink_init(void)
+{
+        printk("Netfilter messages via NETLINK v%s.\n", nfversion);
+        return register_pernet_subsys(&nfnetlink_net_ops);
 }
 
+static void __exit nfnetlink_exit(void)
+{
+        printk("Removing netfilter NETLINK layer.\n");
+        unregister_pernet_subsys(&nfnetlink_net_ops);
+}
 module_init(nfnetlink_init);
 module_exit(nfnetlink_exit);
diff --git a/net/netfilter/nfnetlink_log.c b/net/netfilter/nfnetlink_log.c
index 9de0470d557e..285e9029a9ff 100644
--- a/net/netfilter/nfnetlink_log.c
+++ b/net/netfilter/nfnetlink_log.c
@@ -323,7 +323,8 @@ __nfulnl_send(struct nfulnl_instance *inst)
                           NLMSG_DONE,
                           sizeof(struct nfgenmsg));
 
-        status = nfnetlink_unicast(inst->skb, inst->peer_pid, MSG_DONTWAIT);
+        status = nfnetlink_unicast(inst->skb, &init_net, inst->peer_pid,
+                                   MSG_DONTWAIT);
 
         inst->qlen = 0;
         inst->skb = NULL;
diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c
index 7e3fa410641e..5c589b27d6eb 100644
--- a/net/netfilter/nfnetlink_queue.c
+++ b/net/netfilter/nfnetlink_queue.c
@@ -420,7 +420,7 @@ nfqnl_enqueue_packet(struct nf_queue_entry *entry, unsigned int queuenum)
         }
 
         /* nfnetlink_unicast will either free the nskb or add it to a socket */
-        err = nfnetlink_unicast(nskb, queue->peer_pid, MSG_DONTWAIT);
+        err = nfnetlink_unicast(nskb, &init_net, queue->peer_pid, MSG_DONTWAIT);
         if (err < 0) {
                 queue->queue_user_dropped++;
                 goto err_out_unlock;