[PATCH] net: vrf: Make add_fib_rules per network namespace flag

[David Ahern]

Commit 1aa6c4f6b8cd8 ("net: vrf: Add l3mdev rules on first device create")
adds the l3mdev FIB rule the first time a VRF device is created. However,
it only creates the rule once and only in the namespace the first device
is created - which may not be init_net. Fix by using the net_generic
capability to make the add_fib_rules flag per network namespace.

Fixes: 1aa6c4f6b8cd8 ("net: vrf: Add l3mdev rules on first device create")
Reported-by: Petr Machata <pe...@mellanox.com>
Signed-off-by: David Ahern <dsah...@gmail.com>
---
 drivers/net/vrf.c | 36 ++++++++++++++++++++++++++++++++----
 1 file changed, 32 insertions(+), 4 deletions(-)

diff --git a/drivers/net/vrf.c b/drivers/net/vrf.c
index db882493875c..73b36f579867 100644
--- a/drivers/net/vrf.c
+++ b/drivers/net/vrf.c
@@ -36,12 +36,14 @@
 #include <net/addrconf.h>
 #include <net/l3mdev.h>
 #include <net/fib_rules.h>
+#include <net/netns/generic.h>
 
 #define DRV_NAME       "vrf"
 #define DRV_VERSION    "1.0"
 
 #define FIB_RULE_PREF  1000       /* default preference for FIB rules */
-static bool add_fib_rules = true;
+
+static unsigned int vrf_net_id;
 
 struct net_vrf {
        struct rtable __rcu     *rth;
@@ -1394,6 +1396,8 @@ static int vrf_newlink(struct net *src_net, struct 
net_device *dev,
                       struct nlattr *tb[], struct nlattr *data[])
 {
        struct net_vrf *vrf = netdev_priv(dev);
+       bool *add_fib_rules;
+       struct net *net;
        int err;
 
        if (!data || !data[IFLA_VRF_TABLE])
@@ -1409,13 +1413,15 @@ static int vrf_newlink(struct net *src_net, struct 
net_device *dev,
        if (err)
                goto out;
 
-       if (add_fib_rules) {
+       net = dev_net(dev);
+       add_fib_rules = net_generic(net, vrf_net_id);
+       if (*add_fib_rules) {
                err = vrf_add_fib_rules(dev);
                if (err) {
                        unregister_netdevice(dev);
                        goto out;
                }
-               add_fib_rules = false;
+               *add_fib_rules = false;
        }
 
 out:
@@ -1498,16 +1504,38 @@ static struct notifier_block vrf_notifier_block 
__read_mostly = {
        .notifier_call = vrf_device_event,
 };
 
+/* Initialize per network namespace state */
+static int __net_init vrf_netns_init(struct net *net)
+{
+       bool *add_fib_rules = net_generic(net, vrf_net_id);
+
+       *add_fib_rules = true;
+
+       return 0;
+}
+
+static struct pernet_operations vrf_net_ops __net_initdata = {
+       .init = vrf_netns_init,
+       .id   = &vrf_net_id,
+       .size = sizeof(bool),
+};
+
 static int __init vrf_init_module(void)
 {
        int rc;
 
        register_netdevice_notifier(&vrf_notifier_block);
 
-       rc = rtnl_link_register(&vrf_link_ops);
+       rc = register_pernet_subsys(&vrf_net_ops);
        if (rc < 0)
                goto error;
 
+       rc = rtnl_link_register(&vrf_link_ops);
+       if (rc < 0) {
+               unregister_pernet_subsys(&vrf_net_ops);
+               goto error;
+       }
+
        return 0;
 
 error:
-- 
2.11.0 (Apple Git-81)