[NET]: Make rtnetlink infrastructure network namespace aware (v3)
After this patch none of the netlink callback support anything
except the initial network namespace but the rtnetlink infrastructure
now handles multiple network namespaces.
Changes from v2:
- IPv6 addrlabel processing
Changes from v1:
- no need for special rtnl_unlock handling
- fixed IPv6 ndisc
Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 4edc3da..9efaf35 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -60,7 +60,6 @@
};
static DEFINE_MUTEX(rtnl_mutex);
-static struct sock *rtnl;
void rtnl_lock(void)
{
@@ -458,8 +457,9 @@
return ret;
}
-int rtnetlink_send(struct sk_buff *skb, u32 pid, unsigned group, int echo)
+int rtnetlink_send(struct sk_buff *skb, struct net *net, u32 pid, unsigned group, int echo)
{
+ struct sock *rtnl = net->rtnl;
int err = 0;
NETLINK_CB(skb).dst_group = group;
@@ -471,14 +471,17 @@
return err;
}
-int rtnl_unicast(struct sk_buff *skb, u32 pid)
+int rtnl_unicast(struct sk_buff *skb, struct net *net, u32 pid)
{
+ struct sock *rtnl = net->rtnl;
+
return nlmsg_unicast(rtnl, skb, pid);
}
-int rtnl_notify(struct sk_buff *skb, u32 pid, u32 group,
+int rtnl_notify(struct sk_buff *skb, struct net *net, u32 pid, u32 group,
struct nlmsghdr *nlh, gfp_t flags)
{
+ struct sock *rtnl = net->rtnl;
int report = 0;
if (nlh)
@@ -487,8 +490,10 @@
return nlmsg_notify(rtnl, skb, pid, group, report, flags);
}
-void rtnl_set_sk_err(u32 group, int error)
+void rtnl_set_sk_err(struct net *net, u32 group, int error)
{
+ struct sock *rtnl = net->rtnl;
+
netlink_set_err(rtnl, 0, group, error);
}
@@ -1201,7 +1206,7 @@
kfree_skb(nskb);
goto errout;
}
- err = rtnl_unicast(nskb, NETLINK_CB(skb).pid);
+ err = rtnl_unicast(nskb, net, NETLINK_CB(skb).pid);
errout:
dev_put(dev);
@@ -1252,10 +1257,10 @@
kfree_skb(skb);
goto errout;
}
- err = rtnl_notify(skb, 0, RTNLGRP_LINK, NULL, GFP_KERNEL);
+ err = rtnl_notify(skb, &init_net, 0, RTNLGRP_LINK, NULL, GFP_KERNEL);
errout:
if (err < 0)
- rtnl_set_sk_err(RTNLGRP_LINK, err);
+ rtnl_set_sk_err(&init_net, RTNLGRP_LINK, err);
}
/* Protected by RTNL sempahore. */
@@ -1266,6 +1271,7 @@
static int rtnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
{
+ struct net *net = skb->sk->sk_net;
rtnl_doit_func doit;
int sz_idx, kind;
int min_len;
@@ -1294,6 +1300,7 @@
return -EPERM;
if (kind == 2 && nlh->nlmsg_flags&NLM_F_DUMP) {
+ struct sock *rtnl;
rtnl_dumpit_func dumpit;
dumpit = rtnl_get_dumpit(family, type);
@@ -1301,6 +1308,7 @@
return -EOPNOTSUPP;
__rtnl_unlock();
+ rtnl = net->rtnl;
err = netlink_dump_start(rtnl, skb, nlh, dumpit, NULL);
rtnl_lock();
return err;
@@ -1373,6 +1381,40 @@
.notifier_call = rtnetlink_event,
};
+
+static int rtnetlink_net_init(struct net *net)
+{
+ struct sock *sk;
+ sk = netlink_kernel_create(net, NETLINK_ROUTE, RTNLGRP_MAX,
+ rtnetlink_rcv, &rtnl_mutex, THIS_MODULE);
+ if (!sk)
+ return -ENOMEM;
+
+ /* Don't hold an extra reference on the namespace */
+ put_net(sk->sk_net);
+ net->rtnl = sk;
+ return 0;
+}
+
+static void rtnetlink_net_exit(struct net *net)
+{
+ struct sock *sk = net->rtnl;
+ if (sk) {
+ /* At the last minute lie and say this is a socket for the
+ * initial network namespace. So the socket will be safe to
+ * free.
+ */
+ sk->sk_net = get_net(&init_net);
+ sock_put(sk);
+ net->rtnl = NULL;
+ }
+}
+
+static struct pernet_operations rtnetlink_net_ops = {
+ .init = rtnetlink_net_init,
+ .exit = rtnetlink_net_exit,
+};
+
void __init rtnetlink_init(void)
{
int i;
@@ -1385,10 +1427,9 @@
if (!rta_buf)
panic("rtnetlink_init: cannot allocate rta_buf\n");
- rtnl = netlink_kernel_create(&init_net, NETLINK_ROUTE, RTNLGRP_MAX,
- rtnetlink_rcv, &rtnl_mutex, THIS_MODULE);
- if (rtnl == NULL)
+ if (register_pernet_subsys(&rtnetlink_net_ops))
panic("rtnetlink_init: cannot initialize rtnetlink\n");
+
netlink_set_nonroot(NETLINK_ROUTE, NL_NONROOT_RECV);
register_netdevice_notifier(&rtnetlink_dev_notifier);