From 745041e2aaf1d668f293aaab4b0f6ad7daa056a5 Mon Sep 17 00:00:00 2001 From: Robert Shearman Date: Fri, 19 Feb 2016 09:43:16 +0000 Subject: [PATCH] lwtunnel: autoload of lwt modules 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 Signed-off-by: David S. Miller --- 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 #include +#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(); -- 2.20.1