xfrm: remove type and offload_type map from xfrm_state_afinfo

Only a handful of xfrm_types exist, no need to have 512 pointers for them.

Reduces size of afinfo struct from 4k to 120 bytes on 64bit platforms.

Also, the unregister function doesn't need to return an error, no single
caller does anything useful with it.

Just place a WARN_ON() where needed instead.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>

1 files changed, 127 insertions, 52 deletions

diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c
index 3f0950db060a..fd51737f9f17 100644
--- a/net/xfrm/xfrm_state.c
+++ b/net/xfrm/xfrm_state.c
@@ -177,63 +177,132 @@ int km_query(struct xfrm_state *x, struct xfrm_tmpl *t, struct xfrm_policy *pol)
 static bool km_is_alive(const struct km_event *c);
 void km_state_expired(struct xfrm_state *x, int hard, u32 portid);
 
-static DEFINE_SPINLOCK(xfrm_type_lock);
 int xfrm_register_type(const struct xfrm_type *type, unsigned short family)
 {
 	struct xfrm_state_afinfo *afinfo = xfrm_state_get_afinfo(family);
-	const struct xfrm_type **typemap;
 	int err = 0;
 
-	if (unlikely(afinfo == NULL))
+	if (!afinfo)
 		return -EAFNOSUPPORT;
-	typemap = afinfo->type_map;
-	spin_lock_bh(&xfrm_type_lock);
 
-	if (likely(typemap[type->proto] == NULL))
-		typemap[type->proto] = type;
-	else
-		err = -EEXIST;
-	spin_unlock_bh(&xfrm_type_lock);
+#define X(afi, T, name) do {			\
+		WARN_ON((afi)->type_ ## name);	\
+		(afi)->type_ ## name = (T);	\
+	} while (0)
+
+	switch (type->proto) {
+	case IPPROTO_COMP:
+		X(afinfo, type, comp);
+		break;
+	case IPPROTO_AH:
+		X(afinfo, type, ah);
+		break;
+	case IPPROTO_ESP:
+		X(afinfo, type, esp);
+		break;
+	case IPPROTO_IPIP:
+		X(afinfo, type, ipip);
+		break;
+	case IPPROTO_DSTOPTS:
+		X(afinfo, type, dstopts);
+		break;
+	case IPPROTO_ROUTING:
+		X(afinfo, type, routing);
+		break;
+	case IPPROTO_IPV6:
+		X(afinfo, type, ipip6);
+		break;
+	default:
+		WARN_ON(1);
+		err = -EPROTONOSUPPORT;
+		break;
+	}
+#undef X
 	rcu_read_unlock();
 	return err;
 }
 EXPORT_SYMBOL(xfrm_register_type);
 
-int xfrm_unregister_type(const struct xfrm_type *type, unsigned short family)
+void xfrm_unregister_type(const struct xfrm_type *type, unsigned short family)
 {
 	struct xfrm_state_afinfo *afinfo = xfrm_state_get_afinfo(family);
-	const struct xfrm_type **typemap;
-	int err = 0;
 
 	if (unlikely(afinfo == NULL))
-		return -EAFNOSUPPORT;
-	typemap = afinfo->type_map;
-	spin_lock_bh(&xfrm_type_lock);
+		return;
 
-	if (unlikely(typemap[type->proto] != type))
-		err = -ENOENT;
-	else
-		typemap[type->proto] = NULL;
-	spin_unlock_bh(&xfrm_type_lock);
+#define X(afi, T, name) do {				\
+		WARN_ON((afi)->type_ ## name != (T));	\
+		(afi)->type_ ## name = NULL;		\
+	} while (0)
+
+	switch (type->proto) {
+	case IPPROTO_COMP:
+		X(afinfo, type, comp);
+		break;
+	case IPPROTO_AH:
+		X(afinfo, type, ah);
+		break;
+	case IPPROTO_ESP:
+		X(afinfo, type, esp);
+		break;
+	case IPPROTO_IPIP:
+		X(afinfo, type, ipip);
+		break;
+	case IPPROTO_DSTOPTS:
+		X(afinfo, type, dstopts);
+		break;
+	case IPPROTO_ROUTING:
+		X(afinfo, type, routing);
+		break;
+	case IPPROTO_IPV6:
+		X(afinfo, type, ipip6);
+		break;
+	default:
+		WARN_ON(1);
+		break;
+	}
+#undef X
 	rcu_read_unlock();
-	return err;
 }
 EXPORT_SYMBOL(xfrm_unregister_type);
 
 static const struct xfrm_type *xfrm_get_type(u8 proto, unsigned short family)
 {
+	const struct xfrm_type *type = NULL;
 	struct xfrm_state_afinfo *afinfo;
-	const struct xfrm_type **typemap;
-	const struct xfrm_type *type;
 	int modload_attempted = 0;
 
 retry:
 	afinfo = xfrm_state_get_afinfo(family);
 	if (unlikely(afinfo == NULL))
 		return NULL;
-	typemap = afinfo->type_map;
 
-	type = READ_ONCE(typemap[proto]);
+	switch (proto) {
+	case IPPROTO_COMP:
+		type = afinfo->type_comp;
+		break;
+	case IPPROTO_AH:
+		type = afinfo->type_ah;
+		break;
+	case IPPROTO_ESP:
+		type = afinfo->type_esp;
+		break;
+	case IPPROTO_IPIP:
+		type = afinfo->type_ipip;
+		break;
+	case IPPROTO_DSTOPTS:
+		type = afinfo->type_dstopts;
+		break;
+	case IPPROTO_ROUTING:
+		type = afinfo->type_routing;
+		break;
+	case IPPROTO_IPV6:
+		type = afinfo->type_ipip6;
+		break;
+	default:
+		break;
+	}
+
 	if (unlikely(type && !try_module_get(type->owner)))
 		type = NULL;
 
@@ -253,65 +322,71 @@ static void xfrm_put_type(const struct xfrm_type *type)
 	module_put(type->owner);
 }
 
-static DEFINE_SPINLOCK(xfrm_type_offload_lock);
 int xfrm_register_type_offload(const struct xfrm_type_offload *type,
 			       unsigned short family)
 {
 	struct xfrm_state_afinfo *afinfo = xfrm_state_get_afinfo(family);
-	const struct xfrm_type_offload **typemap;
 	int err = 0;
 
 	if (unlikely(afinfo == NULL))
 		return -EAFNOSUPPORT;
-	typemap = afinfo->type_offload_map;
-	spin_lock_bh(&xfrm_type_offload_lock);
 
-	if (likely(typemap[type->proto] == NULL))
-		typemap[type->proto] = type;
-	else
-		err = -EEXIST;
-	spin_unlock_bh(&xfrm_type_offload_lock);
+	switch (type->proto) {
+	case IPPROTO_ESP:
+		WARN_ON(afinfo->type_offload_esp);
+		afinfo->type_offload_esp = type;
+		break;
+	default:
+		WARN_ON(1);
+		err = -EPROTONOSUPPORT;
+		break;
+	}
+
 	rcu_read_unlock();
 	return err;
 }
 EXPORT_SYMBOL(xfrm_register_type_offload);
 
-int xfrm_unregister_type_offload(const struct xfrm_type_offload *type,
-				 unsigned short family)
+void xfrm_unregister_type_offload(const struct xfrm_type_offload *type,
+				  unsigned short family)
 {
 	struct xfrm_state_afinfo *afinfo = xfrm_state_get_afinfo(family);
-	const struct xfrm_type_offload **typemap;
-	int err = 0;
 
 	if (unlikely(afinfo == NULL))
-		return -EAFNOSUPPORT;
-	typemap = afinfo->type_offload_map;
-	spin_lock_bh(&xfrm_type_offload_lock);
+		return;
 
-	if (unlikely(typemap[type->proto] != type))
-		err = -ENOENT;
-	else
-		typemap[type->proto] = NULL;
-	spin_unlock_bh(&xfrm_type_offload_lock);
+	switch (type->proto) {
+	case IPPROTO_ESP:
+		WARN_ON(afinfo->type_offload_esp != type);
+		afinfo->type_offload_esp = NULL;
+		break;
+	default:
+		WARN_ON(1);
+		break;
+	}
 	rcu_read_unlock();
-	return err;
 }
 EXPORT_SYMBOL(xfrm_unregister_type_offload);
 
 static const struct xfrm_type_offload *
 xfrm_get_type_offload(u8 proto, unsigned short family, bool try_load)
 {
+	const struct xfrm_type_offload *type = NULL;
 	struct xfrm_state_afinfo *afinfo;
-	const struct xfrm_type_offload **typemap;
-	const struct xfrm_type_offload *type;
 
 retry:
 	afinfo = xfrm_state_get_afinfo(family);
 	if (unlikely(afinfo == NULL))
 		return NULL;
-	typemap = afinfo->type_offload_map;
 
-	type = typemap[proto];
+	switch (proto) {
+	case IPPROTO_ESP:
+		type = afinfo->type_offload_esp;
+		break;
+	default:
+		break;
+	}
+
 	if ((type && !try_module_get(type->owner)))
 		type = NULL;