[RFC net-next 07/11] ipmr, ip6mr: Unite logic for searching in MFC cache

[Yuval Mintz <yuvalm@mellanox.com>]

ipmr and ip6mr utilize the exact same methods for searching the
hashed resolved connections, difference being only in the construction
of the hash comparison key.

In order to unite the flow, introduce an mr_table operation set that
would contain the protocol specific information required for common
flows, in this case - the hash parameters and a comparison key
representing a (*,*) route.

Signed-off-by: Yuval Mintz <yuvalm@mellanox.com>
---
 include/linux/mroute_base.h | 52 +++++++++++++++++++++++++++++--
 net/ipv4/ipmr.c             | 71 ++++++++++---------------------------------
 net/ipv4/ipmr_base.c        | 54 +++++++++++++++++++++++++++++++--
 net/ipv6/ip6mr.c            | 74 +++++++++++----------------------------------
 4 files changed, 134 insertions(+), 117 deletions(-)

diff --git a/include/linux/mroute_base.h b/include/linux/mroute_base.h
index 2769e2f..18a1d75 100644
--- a/include/linux/mroute_base.h
+++ b/include/linux/mroute_base.h
@@ -89,10 +89,23 @@ struct mr_mfc {
 	struct rcu_head	rcu;
 };
 
+struct mr_table;
+
+/**
+ * struct mr_table_ops - callbacks and info for protocol-specific ops
+ * rht_params: parameters for accessing the MFC hash
+ * cmparg_any: a hash key to be used for matching on (*,*) routes
+ */
+struct mr_table_ops {
+	const struct rhashtable_params *rht_params;
+	void *cmparg_any;
+};
+
 /**
  * struct mr_table - a multicast routing table
  * @list: entry within a list of multicast routing tables
  * @net: net where this table belongs
+ * @op: protocol specific operations
  * @id: identifier of the table
  * @mroute_sk: socket associated with the table
  * @ipmr_expire_timer: timer for handling unresolved routes
@@ -109,6 +122,7 @@ struct mr_mfc {
 struct mr_table {
 	struct list_head	list;
 	possible_net_t		net;
+	struct mr_table_ops	ops;
 	u32			id;
 	struct sock __rcu	*mroute_sk;
 	struct timer_list	ipmr_expire_timer;
@@ -133,10 +147,19 @@ void vif_device_init(struct vif_device *v,
 
 struct mr_table *
 mr_table_alloc(struct net *net, u32 id,
-	       const struct rhashtable_params *rht_params,
+	       struct mr_table_ops *ops,
 	       void (*expire_func)(struct timer_list *t),
 	       void (*table_set)(struct mr_table *mrt,
 				 struct net *net));
+
+/* These actually return 'struct mr_mfc *', but to avoid need for explicit
+ * castings they simply return void.
+ */
+void *mr_mfc_find_parent(struct mr_table *mrt,
+			 void *hasharg, int parent);
+void *mr_mfc_find_any_parent(struct mr_table *mrt, int vifi);
+void *mr_mfc_find_any(struct mr_table *mrt, int vifi, void *hasharg);
+
 #else
 static inline void vif_device_init(struct vif_device *v,
 				   struct net_device *dev,
@@ -147,14 +170,37 @@ static inline void vif_device_init(struct vif_device *v,
 {
 }
 
-static inline struct mr_table *
+static inline void *
 mr_table_alloc(struct net *net, u32 id,
-	       const struct rhashtable_params *rht_params,
+	       struct mr_table_ops *ops,
 	       void (*expire_func)(struct timer_list *t),
 	       void (*table_set)(struct mr_table *mrt,
 				 struct net *net))
 {
 	return NULL;
 }
+
+static inline void *mr_mfc_find_parent(struct mr_table *mrt,
+				       void *hasharg, int parent)
+{
+	return NULL;
+}
+
+static inline void *mr_mfc_find_any_parent(struct mr_table *mrt,
+					   int vifi)
+{
+	return NULL;
+}
+
+static inline struct mr_mfc *mr_mfc_find_any(struct mr_table *mrt,
+					     int vifi, void *hasharg)
+{
+	return NULL;
+}
 #endif
+
+static inline void *mr_mfc_find(struct mr_table *mrt, void *hasharg)
+{
+	return mr_mfc_find_parent(mrt, hasharg, -1);
+}
 #endif
diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c
index a47d061..0df4dd5 100644
--- a/net/ipv4/ipmr.c
+++ b/net/ipv4/ipmr.c
@@ -359,6 +359,16 @@ static void ipmr_new_table_set(struct mr_table *mr,
 #endif
 }
 
+static struct mfc_cache_cmp_arg ipmr_mr_table_ops_cmparg_any = {
+	.mfc_mcastgrp = htonl(INADDR_ANY),
+	.mfc_origin = htonl(INADDR_ANY),
+};
+
+static struct mr_table_ops ipmr_mr_table_ops = {
+	.rht_params = &ipmr_rht_params,
+	.cmparg_any = &ipmr_mr_table_ops_cmparg_any,
+};
+
 static struct mr_table *ipmr_new_table(struct net *net, u32 id)
 {
 	struct mr_table *mrt;
@@ -371,7 +381,7 @@ static struct mr_table *ipmr_new_table(struct net *net, u32 id)
 	if (mrt)
 		return mrt;
 
-	return mr_table_alloc(net, id, &ipmr_rht_params,
+	return mr_table_alloc(net, id, &ipmr_mr_table_ops,
 			      ipmr_expire_process, ipmr_new_table_set);
 }
 
@@ -972,33 +982,8 @@ static struct mfc_cache *ipmr_cache_find(struct mr_table *mrt,
 			.mfc_mcastgrp = mcastgrp,
 			.mfc_origin = origin
 	};
-	struct rhlist_head *tmp, *list;
-	struct mr_mfc *c;
-
-	list = rhltable_lookup(&mrt->mfc_hash, &arg, ipmr_rht_params);
-	rhl_for_each_entry_rcu(c, tmp, list, mnode)
-		return (struct mfc_cache *)c;
-
-	return NULL;
-}
-
-/* Look for a (*,*,oif) entry */
-static struct mfc_cache *ipmr_cache_find_any_parent(struct mr_table *mrt,
-						    int vifi)
-{
-	struct mfc_cache_cmp_arg arg = {
-			.mfc_mcastgrp = htonl(INADDR_ANY),
-			.mfc_origin = htonl(INADDR_ANY)
-	};
-	struct rhlist_head *tmp, *list;
-	struct mr_mfc *c;
-
-	list = rhltable_lookup(&mrt->mfc_hash, &arg, ipmr_rht_params);
-	rhl_for_each_entry_rcu(c, tmp, list, mnode)
-		if (c->mfc_un.res.ttls[vifi] < 255)
-			return (struct mfc_cache *)c;
 
-	return NULL;
+	return mr_mfc_find(mrt, &arg);
 }
 
 /* Look for a (*,G) entry */
@@ -1009,27 +994,10 @@ static struct mfc_cache *ipmr_cache_find_any(struct mr_table *mrt,
 			.mfc_mcastgrp = mcastgrp,
 			.mfc_origin = htonl(INADDR_ANY)
 	};
-	struct rhlist_head *tmp, *list;
-	struct mr_mfc *c;
 
 	if (mcastgrp == htonl(INADDR_ANY))
-		goto skip;
-
-	list = rhltable_lookup(&mrt->mfc_hash, &arg, ipmr_rht_params);
-	rhl_for_each_entry_rcu(c, tmp, list, mnode) {
-		struct mfc_cache *proxy;
-
-		if (c->mfc_un.res.ttls[vifi] < 255)
-			return (struct mfc_cache *)c;
-
-		/* It's ok if the vifi is part of the static tree */
-		proxy = ipmr_cache_find_any_parent(mrt, c->mfc_parent);
-		if (proxy && proxy->_c.mfc_un.res.ttls[vifi] < 255)
-			return (struct mfc_cache *)c;
-	}
-
-skip:
-	return ipmr_cache_find_any_parent(mrt, vifi);
+		return mr_mfc_find_any_parent(mrt, vifi);
+	return mr_mfc_find_any(mrt, vifi, &arg);
 }
 
 /* Look for a (S,G,iif) entry if parent != -1 */
@@ -1041,15 +1009,8 @@ static struct mfc_cache *ipmr_cache_find_parent(struct mr_table *mrt,
 			.mfc_mcastgrp = mcastgrp,
 			.mfc_origin = origin,
 	};
-	struct rhlist_head *tmp, *list;
-	struct mr_mfc *c;
 
-	list = rhltable_lookup(&mrt->mfc_hash, &arg, ipmr_rht_params);
-	rhl_for_each_entry_rcu(c, tmp, list, mnode)
-		if (parent == -1 || parent == c->mfc_parent)
-			return (struct mfc_cache *)c;
-
-	return NULL;
+	return mr_mfc_find_parent(mrt, &arg, parent);
 }
 
 /* Allocate a multicast cache entry */
@@ -2010,7 +1971,7 @@ static void ip_mr_forward(struct net *net, struct mr_table *mrt,
 		/* For an (*,G) entry, we only check that the incomming
 		 * interface is part of the static tree.
 		 */
-		cache_proxy = ipmr_cache_find_any_parent(mrt, vif);
+		cache_proxy = mr_mfc_find_any_parent(mrt, vif);
 		if (cache_proxy &&
 		    cache_proxy->_c.mfc_un.res.ttls[true_vifi] < 255)
 			goto forward;
diff --git a/net/ipv4/ipmr_base.c b/net/ipv4/ipmr_base.c
index 3e21a58..172f92a 100644
--- a/net/ipv4/ipmr_base.c
+++ b/net/ipv4/ipmr_base.c
@@ -29,7 +29,7 @@ EXPORT_SYMBOL(vif_device_init);
 
 struct mr_table *
 mr_table_alloc(struct net *net, u32 id,
-	       const struct rhashtable_params *rht_params,
+	       struct mr_table_ops *ops,
 	       void (*expire_func)(struct timer_list *t),
 	       void (*table_set)(struct mr_table *mrt,
 				 struct net *net))
@@ -42,7 +42,8 @@ mr_table_alloc(struct net *net, u32 id,
 	mrt->id = id;
 	write_pnet(&mrt->net, net);
 
-	rhltable_init(&mrt->mfc_hash, rht_params);
+	mrt->ops = *ops;
+	rhltable_init(&mrt->mfc_hash, mrt->ops.rht_params);
 	INIT_LIST_HEAD(&mrt->mfc_cache_list);
 	INIT_LIST_HEAD(&mrt->mfc_unres_queue);
 
@@ -53,3 +54,52 @@ mr_table_alloc(struct net *net, u32 id,
 	return mrt;
 }
 EXPORT_SYMBOL(mr_table_alloc);
+
+void *mr_mfc_find_parent(struct mr_table *mrt, void *hasharg, int parent)
+{
+	struct rhlist_head *tmp, *list;
+	struct mr_mfc *c;
+
+	list = rhltable_lookup(&mrt->mfc_hash, hasharg, *mrt->ops.rht_params);
+	rhl_for_each_entry_rcu(c, tmp, list, mnode)
+		if (parent == -1 || parent == c->mfc_parent)
+			return c;
+
+	return NULL;
+}
+EXPORT_SYMBOL(mr_mfc_find_parent);
+
+void *mr_mfc_find_any_parent(struct mr_table *mrt, int vifi)
+{
+	struct rhlist_head *tmp, *list;
+	struct mr_mfc *c;
+
+	list = rhltable_lookup(&mrt->mfc_hash, mrt->ops.cmparg_any,
+			       *mrt->ops.rht_params);
+	rhl_for_each_entry_rcu(c, tmp, list, mnode)
+		if (c->mfc_un.res.ttls[vifi] < 255)
+			return c;
+
+	return NULL;
+}
+EXPORT_SYMBOL(mr_mfc_find_any_parent);
+
+void *mr_mfc_find_any(struct mr_table *mrt, int vifi, void *hasharg)
+{
+	struct rhlist_head *tmp, *list;
+	struct mr_mfc *c, *proxy;
+
+	list = rhltable_lookup(&mrt->mfc_hash, hasharg, *mrt->ops.rht_params);
+	rhl_for_each_entry_rcu(c, tmp, list, mnode) {
+		if (c->mfc_un.res.ttls[vifi] < 255)
+			return c;
+
+		/* It's ok if the vifi is part of the static tree */
+		proxy = mr_mfc_find_any_parent(mrt, c->mfc_parent);
+		if (proxy && proxy->mfc_un.res.ttls[vifi] < 255)
+			return c;
+	}
+
+	return mr_mfc_find_any_parent(mrt, vifi);
+}
+EXPORT_SYMBOL(mr_mfc_find_any);
diff --git a/net/ipv6/ip6mr.c b/net/ipv6/ip6mr.c
index 8ed97d8..4ea3f75 100644
--- a/net/ipv6/ip6mr.c
+++ b/net/ipv6/ip6mr.c
@@ -302,6 +302,16 @@ static void ip6mr_new_table_set(struct mr_table *mrt,
 #endif
 }
 
+struct mfc6_cache_cmp_arg ip6mr_mr_table_ops_cmparg_any = {
+	.mf6c_origin = IN6ADDR_ANY_INIT,
+	.mf6c_mcastgrp = IN6ADDR_ANY_INIT,
+};
+
+static struct mr_table_ops ip6mr_mr_table_ops = {
+	.rht_params = &ip6mr_rht_params,
+	.cmparg_any = &ip6mr_mr_table_ops_cmparg_any,
+};
+
 static struct mr_table *ip6mr_new_table(struct net *net, u32 id)
 {
 	struct mr_table *mrt;
@@ -310,7 +320,7 @@ static struct mr_table *ip6mr_new_table(struct net *net, u32 id)
 	if (mrt)
 		return mrt;
 
-	return mr_table_alloc(net, id, &ip6mr_rht_params,
+	return mr_table_alloc(net, id, &ip6mr_mr_table_ops,
 			      ipmr_expire_process, ip6mr_new_table_set);
 }
 
@@ -988,33 +998,8 @@ static struct mfc6_cache *ip6mr_cache_find(struct mr_table *mrt,
 		.mf6c_origin = *origin,
 		.mf6c_mcastgrp = *mcastgrp,
 	};
-	struct rhlist_head *tmp, *list;
-	struct mr_mfc *c;
-
-	list = rhltable_lookup(&mrt->mfc_hash, &arg, ip6mr_rht_params);
-	rhl_for_each_entry_rcu(c, tmp, list, mnode)
-		return (struct mfc6_cache *)c;
 
-	return NULL;
-}
-
-/* Look for a (*,*,oif) entry */
-static struct mfc6_cache *ip6mr_cache_find_any_parent(struct mr_table *mrt,
-						      mifi_t mifi)
-{
-	struct mfc6_cache_cmp_arg arg = {
-		.mf6c_origin = in6addr_any,
-		.mf6c_mcastgrp = in6addr_any,
-	};
-	struct rhlist_head *tmp, *list;
-	struct mr_mfc *c;
-
-	list = rhltable_lookup(&mrt->mfc_hash, &arg, ip6mr_rht_params);
-	rhl_for_each_entry_rcu(c, tmp, list, mnode)
-		if (c->mfc_un.res.ttls[mifi] < 255)
-			return (struct mfc6_cache *)c;
-
-	return NULL;
+	return mr_mfc_find(mrt, &arg);
 }
 
 /* Look for a (*,G) entry */
@@ -1026,26 +1011,10 @@ static struct mfc6_cache *ip6mr_cache_find_any(struct mr_table *mrt,
 		.mf6c_origin = in6addr_any,
 		.mf6c_mcastgrp = *mcastgrp,
 	};
-	struct rhlist_head *tmp, *list;
-	struct mr_mfc *c;
-	struct mfc6_cache *proxy;
 
 	if (ipv6_addr_any(mcastgrp))
-		goto skip;
-
-	list = rhltable_lookup(&mrt->mfc_hash, &arg, ip6mr_rht_params);
-	rhl_for_each_entry_rcu(c, tmp, list, mnode) {
-		if (c->mfc_un.res.ttls[mifi] < 255)
-			return (struct mfc6_cache *)c;
-
-		/* It's ok if the mifi is part of the static tree */
-		proxy = ip6mr_cache_find_any_parent(mrt, c->mfc_parent);
-		if (proxy && proxy->_c.mfc_un.res.ttls[mifi] < 255)
-			return (struct mfc6_cache *)c;
-	}
-
-skip:
-	return ip6mr_cache_find_any_parent(mrt, mifi);
+		return mr_mfc_find_any_parent(mrt, mifi);
+	return mr_mfc_find_any(mrt, mifi, &arg);
 }
 
 /* Look for a (S,G,iif) entry if parent != -1 */
@@ -1059,20 +1028,11 @@ ip6mr_cache_find_parent(struct mr_table *mrt,
 		.mf6c_origin = *origin,
 		.mf6c_mcastgrp = *mcastgrp,
 	};
-	struct rhlist_head *tmp, *list;
-	struct mr_mfc *c;
-
-	list = rhltable_lookup(&mrt->mfc_hash, &arg, ip6mr_rht_params);
-	rhl_for_each_entry_rcu(c, tmp, list, mnode)
-		if (parent == -1 || parent == c->mfc_parent)
-			return (struct mfc6_cache *)c;
 
-	return NULL;
+	return mr_mfc_find_parent(mrt, &arg, parent);
 }
 
-/*
- *	Allocate a multicast cache entry
- */
+/* Allocate a multicast cache entry */
 static struct mfc6_cache *ip6mr_cache_alloc(void)
 {
 	struct mfc6_cache *c = kmem_cache_zalloc(mrt_cachep, GFP_KERNEL);
@@ -2112,7 +2072,7 @@ static void ip6_mr_forward(struct net *net, struct mr_table *mrt,
 		 * interface is part of the static tree.
 		 */
 		rcu_read_lock();
-		cache_proxy = ip6mr_cache_find_any_parent(mrt, vif);
+		cache_proxy = mr_mfc_find_any_parent(mrt, vif);
 		if (cache_proxy &&
 		    cache_proxy->_c.mfc_un.res.ttls[true_vifi] < 255) {
 			rcu_read_unlock();
-- 
2.4.3