vrf: Handle CONFIG_SYSCTL not set

Randy reported compile failure when CONFIG_SYSCTL is not set/enabled:

ERROR: modpost: "sysctl_vals" [drivers/net/vrf.ko] undefined!

Fix by splitting out the sysctl init and cleanup into helpers that
can be set to do nothing when CONFIG_SYSCTL is disabled. In addition,
move vrf_strict_mode and vrf_strict_mode_change to above
vrf_shared_table_handler (code move only) and wrap all of it
in the ifdef CONFIG_SYSCTL.

Update the strict mode tests to check for the existence of the
/proc/sys entry.

Fixes: 33306f1aaf82 ("vrf: add sysctl parameter for strict mode")
Cc: Andrea Mayer <andrea.mayer@uniroma2.it>
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: David Ahern <dsahern@kernel.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org> # build-tested
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/vrf.c b/drivers/net/vrf.c
index 4659960..60c1aad 100644 (file)
--- a/drivers/net/vrf.c
+++ b/drivers/net/vrf.c
@@ -260,52 +260,6 @@ static void vrf_map_unlock(struct vrf_map *vmap) __releases(&vmap->vmap_lock)
        spin_unlock(&vmap->vmap_lock);
 }
 
-static bool vrf_strict_mode(struct vrf_map *vmap)
-{
-       bool strict_mode;
-
-       vrf_map_lock(vmap);
-       strict_mode = vmap->strict_mode;
-       vrf_map_unlock(vmap);
-
-       return strict_mode;
-}
-
-static int vrf_strict_mode_change(struct vrf_map *vmap, bool new_mode)
-{
-       bool *cur_mode;
-       int res = 0;
-
-       vrf_map_lock(vmap);
-
-       cur_mode = &vmap->strict_mode;
-       if (*cur_mode == new_mode)
-               goto unlock;
-
-       if (*cur_mode) {
-               /* disable strict mode */
-               *cur_mode = false;
-       } else {
-               if (vmap->shared_tables) {
-                       /* we cannot allow strict_mode because there are some
-                        * vrfs that share one or more tables.
-                        */
-                       res = -EBUSY;
-                       goto unlock;
-               }
-
-               /* no tables are shared among vrfs, so we can go back
-                * to 1:1 association between a vrf with its table.
-                */
-               *cur_mode = true;
-       }
-
-unlock:
-       vrf_map_unlock(vmap);
-
-       return res;
-}
-
 /* called with rtnl lock held */
 static int
 vrf_map_register_dev(struct net_device *dev, struct netlink_ext_ack *extack)
@@ -1790,6 +1744,53 @@ static int vrf_map_init(struct vrf_map *vmap)
        return 0;
 }
 
+#ifdef CONFIG_SYSCTL
+static bool vrf_strict_mode(struct vrf_map *vmap)
+{
+       bool strict_mode;
+
+       vrf_map_lock(vmap);
+       strict_mode = vmap->strict_mode;
+       vrf_map_unlock(vmap);
+
+       return strict_mode;
+}
+
+static int vrf_strict_mode_change(struct vrf_map *vmap, bool new_mode)
+{
+       bool *cur_mode;
+       int res = 0;
+
+       vrf_map_lock(vmap);
+
+       cur_mode = &vmap->strict_mode;
+       if (*cur_mode == new_mode)
+               goto unlock;
+
+       if (*cur_mode) {
+               /* disable strict mode */
+               *cur_mode = false;
+       } else {
+               if (vmap->shared_tables) {
+                       /* we cannot allow strict_mode because there are some
+                        * vrfs that share one or more tables.
+                        */
+                       res = -EBUSY;
+                       goto unlock;
+               }
+
+               /* no tables are shared among vrfs, so we can go back
+                * to 1:1 association between a vrf with its table.
+                */
+               *cur_mode = true;
+       }
+
+unlock:
+       vrf_map_unlock(vmap);
+
+       return res;
+}
+
 static int vrf_shared_table_handler(struct ctl_table *table, int write,
                                    void *buffer, size_t *lenp, loff_t *ppos)
 {
@@ -1830,15 +1831,9 @@ static const struct ctl_table vrf_table[] = {
        { },
 };
 
-/* Initialize per network namespace state */
-static int __net_init vrf_netns_init(struct net *net)
+static int vrf_netns_init_sysctl(struct net *net, struct netns_vrf *nn_vrf)
 {
-       struct netns_vrf *nn_vrf = net_generic(net, vrf_net_id);
        struct ctl_table *table;
-       int res;
-
-       nn_vrf->add_fib_rules = true;
-       vrf_map_init(&nn_vrf->vmap);
 
        table = kmemdup(vrf_table, sizeof(vrf_table), GFP_KERNEL);
        if (!table)
@@ -1849,19 +1844,14 @@ static int __net_init vrf_netns_init(struct net *net)
 
        nn_vrf->ctl_hdr = register_net_sysctl(net, "net/vrf", table);
        if (!nn_vrf->ctl_hdr) {
-               res = -ENOMEM;
-               goto free_table;
+               kfree(table);
+               return -ENOMEM;
        }
 
        return 0;
-
-free_table:
-       kfree(table);
-
-       return res;
 }
 
-static void __net_exit vrf_netns_exit(struct net *net)
+static void vrf_netns_exit_sysctl(struct net *net)
 {
        struct netns_vrf *nn_vrf = net_generic(net, vrf_net_id);
        struct ctl_table *table;
@@ -1870,6 +1860,32 @@ static void __net_exit vrf_netns_exit(struct net *net)
        unregister_net_sysctl_table(nn_vrf->ctl_hdr);
        kfree(table);
 }
+#else
+static int vrf_netns_init_sysctl(struct net *net, struct netns_vrf *nn_vrf)
+{
+       return 0;
+}
+
+static void vrf_netns_exit_sysctl(struct net *net)
+{
+}
+#endif
+
+/* Initialize per network namespace state */
+static int __net_init vrf_netns_init(struct net *net)
+{
+       struct netns_vrf *nn_vrf = net_generic(net, vrf_net_id);
+
+       nn_vrf->add_fib_rules = true;
+       vrf_map_init(&nn_vrf->vmap);
+
+       return vrf_netns_init_sysctl(net, nn_vrf);
+}
+
+static void __net_exit vrf_netns_exit(struct net *net)
+{
+       vrf_netns_exit_sysctl(net);
+}
 
 static struct pernet_operations vrf_net_ops __net_initdata = {
        .init = vrf_netns_init,

diff --git a/tools/testing/selftests/net/vrf_strict_mode_test.sh b/tools/testing/selftests/net/vrf_strict_mode_test.sh
index 5274f4a..18b982d 100755 (executable)
--- a/tools/testing/selftests/net/vrf_strict_mode_test.sh
+++ b/tools/testing/selftests/net/vrf_strict_mode_test.sh
@@ -379,6 +379,12 @@ if [ ! -x "$(command -v ip)" ]; then
        exit 0
 fi
 
+modprobe vrf &>/dev/null
+if [ ! -e /proc/sys/net/vrf/strict_mode ]; then
+       echo "SKIP: vrf sysctl does not exist"
+       exit 0
+fi
+
 cleanup &> /dev/null
 
 setup