1 files changed, 37 insertions, 0 deletions

diff --git a/net/core/lwtunnel.c b/net/core/lwtunnel.c
index 299cfc24d888..669ecc9f884e 100644
--- a/net/core/lwtunnel.c
+++ b/net/core/lwtunnel.c
@@ -27,6 +27,31 @@
 #include <net/rtnetlink.h>
 #include <net/ip6_fib.h>
 
+#ifdef CONFIG_MODULES
+
+static const char *lwtunnel_encap_str(enum lwtunnel_encap_types encap_type)
+{
+        /* Only lwt encaps implemented without using an interface for
+         * the encap need to return a string here.
+         */
+        switch (encap_type) {
+        case LWTUNNEL_ENCAP_MPLS:
+                return "MPLS";
+        case LWTUNNEL_ENCAP_ILA:
+                return "ILA";
+        case LWTUNNEL_ENCAP_IP6:
+        case LWTUNNEL_ENCAP_IP:
+        case LWTUNNEL_ENCAP_NONE:
+        case __LWTUNNEL_ENCAP_MAX:
+                /* should not have got here */
+                WARN_ON(1);
+                break;
+        }
+        return NULL;
+}
+
+#endif /* CONFIG_MODULES */
+
 struct lwtunnel_state *lwtunnel_state_alloc(int encap_len)
 {
         struct lwtunnel_state *lws;
@@ -85,6 +110,18 @@ int lwtunnel_build_state(struct net_device *dev, u16 encap_type,
         ret = -EOPNOTSUPP;
         rcu_read_lock();
         ops = rcu_dereference(lwtun_encaps[encap_type]);
+#ifdef CONFIG_MODULES
+        if (!ops) {
+                const char *encap_type_str = lwtunnel_encap_str(encap_type);
+
+                if (encap_type_str) {
+                        rcu_read_unlock();
+                        request_module("rtnl-lwt-%s", encap_type_str);
+                        rcu_read_lock();
+                        ops = rcu_dereference(lwtun_encaps[encap_type]);
+                }
+        }
+#endif
         if (likely(ops && ops->build_state))
                 ret = ops->build_state(dev, encap, family, cfg, lws);
         rcu_read_unlock();