The lwt implementations using net devices can autoload using the
existing mechanism using IFLA_INFO_KIND. However, there's no mechanism
that lwt modules not using net devices can use.
Therefore, add the ability to autoload modules registering lwt
operations for lwt implementations not using a net device so that
users don't have to manually load the modules.
Only users with the CAP_NET_ADMIN capability can cause modules to be
loaded, which is ensured by rtnetlink_rcv_msg rejecting non-RTM_GETxxx
messages for users without this capability, and by
lwtunnel_build_state not being called in response to RTM_GETxxx
messages.
Signed-off-by: Robert Shearman <rshea...@brocade.com>
---
include/net/lwtunnel.h | 4 +++-
net/core/lwtunnel.c | 37 +++++++++++++++++++++++++++++++++++++
2 files changed, 40 insertions(+), 1 deletion(-)
diff --git a/include/net/lwtunnel.h b/include/net/lwtunnel.h
index 66350ce3e955..e9f116e29c22 100644
--- a/include/net/lwtunnel.h
+++ b/include/net/lwtunnel.h
@@ -170,6 +170,8 @@ static inline int lwtunnel_input(struct sk_buff *skb)
return -EOPNOTSUPP;
}
-#endif
+#endif /* CONFIG_LWTUNNEL */
+
+#define MODULE_ALIAS_RTNL_LWT(encap_type) MODULE_ALIAS("rtnl-lwt-"
__stringify(encap_type))
#endif /* __NET_LWTUNNEL_H */
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();
--
2.1.4
