[NETNS]: Provide correct namespace for fibnl netlink socket.

This patch makes the netlink socket to be per namespace. That allows
to have each namespace its own socket for routing queries.

Acked-by: Benjamin Thery <benjamin.thery@bull.net>
Acked-by: Daniel Lezcano <dlezcano@fr.ibm.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 16 insertions, 8 deletions

diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c
index 7fe54a3c168b..a5e81677a2b5 100644
--- a/net/ipv4/fib_frontend.c
+++ b/net/ipv4/fib_frontend.c
@@ -49,8 +49,6 @@
 
 #define FFprint(a...) printk(KERN_DEBUG a)
 
-static struct sock *fibnl;
-
 #ifndef CONFIG_IP_MULTIPLE_TABLES
 
 static int __net_init fib4_rules_init(struct net *net)
@@ -845,11 +843,13 @@ static void nl_fib_lookup(struct fib_result_nl *frn, struct fib_table *tb )
 
 static void nl_fib_input(struct sk_buff *skb)
 {
+        struct net *net;
         struct fib_result_nl *frn;
         struct nlmsghdr *nlh;
         struct fib_table *tb;
         u32 pid;
 
+        net = skb->sk->sk_net;
         nlh = nlmsg_hdr(skb);
         if (skb->len < NLMSG_SPACE(0) || skb->len < nlh->nlmsg_len ||
             nlh->nlmsg_len < NLMSG_LENGTH(sizeof(*frn)))
@@ -861,28 +861,36 @@ static void nl_fib_input(struct sk_buff *skb)
         nlh = nlmsg_hdr(skb);
 
         frn = (struct fib_result_nl *) NLMSG_DATA(nlh);
-        tb = fib_get_table(&init_net, frn->tb_id_in);
+        tb = fib_get_table(net, frn->tb_id_in);
 
         nl_fib_lookup(frn, tb);
 
         pid = NETLINK_CB(skb).pid;       /* pid of sending process */
         NETLINK_CB(skb).pid = 0;         /* from kernel */
         NETLINK_CB(skb).dst_group = 0;  /* unicast */
-        netlink_unicast(fibnl, skb, pid, MSG_DONTWAIT);
+        netlink_unicast(net->ipv4.fibnl, skb, pid, MSG_DONTWAIT);
 }
 
 static int nl_fib_lookup_init(struct net *net)
 {
-        fibnl = netlink_kernel_create(net, NETLINK_FIB_LOOKUP, 0,
-                                      nl_fib_input, NULL, THIS_MODULE);
-        if (fibnl == NULL)
+        struct sock *sk;
+        sk = netlink_kernel_create(net, NETLINK_FIB_LOOKUP, 0,
+                                   nl_fib_input, NULL, THIS_MODULE);
+        if (sk == NULL)
                 return -EAFNOSUPPORT;
+        /* Don't hold an extra reference on the namespace */
+        put_net(sk->sk_net);
+        net->ipv4.fibnl = sk;
         return 0;
 }
 
 static void nl_fib_lookup_exit(struct net *net)
 {
-        sock_put(fibnl);
+        /* At the last minute lie and say this is a socket for the
+         * initial network namespace. So the socket will  be safe to free.
+         */
+        net->ipv4.fibnl->sk_net = get_net(&init_net);
+        sock_put(net->ipv4.fibnl);
 }
 
 static void fib_disable_ip(struct net_device *dev, int force)