ip_tunnel: Ops registration for secondary encap (fou, gue)
Instead of calling fou and gue functions directly from ip_tunnel
use ops for these that were previously registered. This patch adds the
logic to add and remove encapsulation operations for ip_tunnel,
and modified fou (and gue) to register with ip_tunnels.
This patch also addresses a circular dependency between ip_tunnel
and fou that was causing link errors when CONFIG_NET_IP_TUNNEL=y
and CONFIG_NET_FOU=m. References to fou an gue have been removed from
ip_tunnel.c
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/ip_tunnel.c b/net/ipv4/ip_tunnel.c
index c3587e1..63e745a 100644
--- a/net/ipv4/ip_tunnel.c
+++ b/net/ipv4/ip_tunnel.c
@@ -57,10 +57,6 @@
#include <net/rtnetlink.h>
#include <net/udp.h>
-#if IS_ENABLED(CONFIG_NET_FOU)
-#include <net/fou.h>
-#endif
-
#if IS_ENABLED(CONFIG_IPV6)
#include <net/ipv6.h>
#include <net/ip6_fib.h>
@@ -494,20 +490,51 @@
static int ip_encap_hlen(struct ip_tunnel_encap *e)
{
- switch (e->type) {
- case TUNNEL_ENCAP_NONE:
+ const struct ip_tunnel_encap_ops *ops;
+ int hlen = -EINVAL;
+
+ if (e->type == TUNNEL_ENCAP_NONE)
return 0;
-#if IS_ENABLED(CONFIG_NET_FOU)
- case TUNNEL_ENCAP_FOU:
- return fou_encap_hlen(e);
- case TUNNEL_ENCAP_GUE:
- return gue_encap_hlen(e);
-#endif
- default:
+
+ if (e->type >= MAX_IPTUN_ENCAP_OPS)
return -EINVAL;
- }
+
+ rcu_read_lock();
+ ops = rcu_dereference(iptun_encaps[e->type]);
+ if (likely(ops && ops->encap_hlen))
+ hlen = ops->encap_hlen(e);
+ rcu_read_unlock();
+
+ return hlen;
}
+const struct ip_tunnel_encap_ops __rcu *
+ iptun_encaps[MAX_IPTUN_ENCAP_OPS] __read_mostly;
+
+int ip_tunnel_encap_add_ops(const struct ip_tunnel_encap_ops *ops,
+ unsigned int num)
+{
+ return !cmpxchg((const struct ip_tunnel_encap_ops **)
+ &iptun_encaps[num],
+ NULL, ops) ? 0 : -1;
+}
+EXPORT_SYMBOL(ip_tunnel_encap_add_ops);
+
+int ip_tunnel_encap_del_ops(const struct ip_tunnel_encap_ops *ops,
+ unsigned int num)
+{
+ int ret;
+
+ ret = (cmpxchg((const struct ip_tunnel_encap_ops **)
+ &iptun_encaps[num],
+ ops, NULL) == ops) ? 0 : -1;
+
+ synchronize_net();
+
+ return ret;
+}
+EXPORT_SYMBOL(ip_tunnel_encap_del_ops);
+
int ip_tunnel_encap_setup(struct ip_tunnel *t,
struct ip_tunnel_encap *ipencap)
{
@@ -534,18 +561,19 @@
int ip_tunnel_encap(struct sk_buff *skb, struct ip_tunnel *t,
u8 *protocol, struct flowi4 *fl4)
{
- switch (t->encap.type) {
- case TUNNEL_ENCAP_NONE:
+ const struct ip_tunnel_encap_ops *ops;
+ int ret = -EINVAL;
+
+ if (t->encap.type == TUNNEL_ENCAP_NONE)
return 0;
-#if IS_ENABLED(CONFIG_NET_FOU)
- case TUNNEL_ENCAP_FOU:
- return fou_build_header(skb, &t->encap, protocol, fl4);
- case TUNNEL_ENCAP_GUE:
- return gue_build_header(skb, &t->encap, protocol, fl4);
-#endif
- default:
- return -EINVAL;
- }
+
+ rcu_read_lock();
+ ops = rcu_dereference(iptun_encaps[t->encap.type]);
+ if (likely(ops && ops->build_header))
+ ret = ops->build_header(skb, &t->encap, protocol, fl4);
+ rcu_read_unlock();
+
+ return ret;
}
EXPORT_SYMBOL(ip_tunnel_encap);