Merge branch 'net-Export-functions-for-nexthop-code'

David Ahern says:

====================
net: Export functions for nexthop code

This set exports ipv4 and ipv6 fib functions for use by the nexthop
code. It also adds new ones to send route notifications if a nexthop
configuration changes.

v2
- repost of patches dropped at the end of the last dev window
  added patch 8 which exports nh_update_mtu since it is inline with
  the other patches
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/ip6_fib.h

@@ -452,6 +452,12 @@ int fib6_nh_init(struct net *net, struct fib6_nh *fib6_nh,
 		 struct netlink_ext_ack *extack);
 void fib6_nh_release(struct fib6_nh *fib6_nh);
 
+int call_fib6_entry_notifiers(struct net *net,
+			      enum fib_event_type event_type,
+			      struct fib6_info *rt,
+			      struct netlink_ext_ack *extack);
+void fib6_rt_update(struct net *net, struct fib6_info *rt,
+		    struct nl_info *info);
 void inet6_rt_notify(int event, struct fib6_info *rt, struct nl_info *info,
 		     unsigned int flags);
 
@@ -485,6 +491,7 @@ int fib6_tables_dump(struct net *net, struct notifier_block *nb);
 
 void fib6_update_sernum(struct net *net, struct fib6_info *rt);
 void fib6_update_sernum_upto_root(struct net *net, struct fib6_info *rt);
+void fib6_update_sernum_stub(struct net *net, struct fib6_info *f6i);
 
 void fib6_metric_set(struct fib6_info *f6i, int metric, u32 val);
 static inline bool fib6_metric_locked(struct fib6_info *f6i, int metric)

include/net/ip_fib.h

@@ -150,6 +150,7 @@ struct fib_info {
 #define fib_advmss fib_metrics->metrics[RTAX_ADVMSS-1]
 	int			fib_nhs;
 	bool			fib_nh_is_v6;
+	bool			nh_updated;
 	struct rcu_head		rcu;
 	struct fib_nh		fib_nh[0];
 #define fib_dev		fib_nh[0].fib_nh_dev
@@ -200,7 +201,8 @@ static inline struct fib_nh_common *fib_info_nhc(struct fib_info *fi, int nhsel)
 #define FIB_TABLE_HASHSZ 2
 #endif
 
-__be32 fib_info_update_nh_saddr(struct net *net, struct fib_nh *nh);
+__be32 fib_info_update_nh_saddr(struct net *net, struct fib_nh *nh,
+				unsigned char scope);
 __be32 fib_result_prefsrc(struct net *net, struct fib_result *res);
 
 #define FIB_RES_NHC(res)		((res).nhc)
@@ -231,6 +233,7 @@ int call_fib4_notifiers(struct net *net, enum fib_event_type event_type,
 int __net_init fib4_notifier_init(struct net *net);
 void __net_exit fib4_notifier_exit(struct net *net);
 
+void fib_info_notify_update(struct net *net, struct nl_info *info);
 void fib_notify(struct net *net, struct notifier_block *nb);
 
 struct fib_table {
@@ -429,11 +432,14 @@ int fib_sync_down_dev(struct net_device *dev, unsigned long event, bool force);
 int fib_sync_down_addr(struct net_device *dev, __be32 local);
 int fib_sync_up(struct net_device *dev, unsigned char nh_flags);
 void fib_sync_mtu(struct net_device *dev, u32 orig_mtu);
+void fib_nhc_update_mtu(struct fib_nh_common *nhc, u32 new, u32 orig);
 
 #ifdef CONFIG_IP_ROUTE_MULTIPATH
 int fib_multipath_hash(const struct net *net, const struct flowi4 *fl4,
 		       const struct sk_buff *skb, struct flow_keys *flkeys);
 #endif
+int fib_check_nh(struct net *net, struct fib_nh *nh, u32 table, u8 scope,
+		 struct netlink_ext_ack *extack);
 void fib_select_multipath(struct fib_result *res, int hash);
 void fib_select_path(struct net *net, struct fib_result *res,
 		     struct flowi4 *fl4, const struct sk_buff *skb);
@@ -469,6 +475,7 @@ static inline void fib_combine_itag(u32 *itag, const struct fib_result *res)
 #endif
 }
 
+void fib_flush(struct net *net);
 void free_fib_info(struct fib_info *fi);
 
 static inline void fib_info_hold(struct fib_info *fi)

include/net/ipv6_stubs.h

@@ -45,6 +45,11 @@ struct ipv6_stub {
 			    struct fib6_config *cfg, gfp_t gfp_flags,
 			    struct netlink_ext_ack *extack);
 	void (*fib6_nh_release)(struct fib6_nh *fib6_nh);
+	void (*fib6_update_sernum)(struct net *net, struct fib6_info *rt);
+	int (*ip6_del_rt)(struct net *net, struct fib6_info *rt);
+	void (*fib6_rt_update)(struct net *net, struct fib6_info *rt,
+			       struct nl_info *info);
+
 	void (*udpv6_encap_enable)(void);
 	void (*ndisc_send_na)(struct net_device *dev, const struct in6_addr *daddr,
 			      const struct in6_addr *solicited_addr,

net/ipv4/fib_frontend.c

@@ -192,7 +192,7 @@ int fib_unmerge(struct net *net)
 	return 0;
 }
 
-static void fib_flush(struct net *net)
+void fib_flush(struct net *net)
 {
 	int flushed = 0;
 	unsigned int h;

net/ipv4/fib_semantics.c

@@ -1092,15 +1092,13 @@ static int fib_check_nh_nongw(struct net *net, struct fib_nh *nh,
 	return err;
 }
 
-static int fib_check_nh(struct fib_config *cfg, struct fib_nh *nh,
-			struct netlink_ext_ack *extack)
+int fib_check_nh(struct net *net, struct fib_nh *nh, u32 table, u8 scope,
+		 struct netlink_ext_ack *extack)
 {
-	struct net *net = cfg->fc_nlinfo.nl_net;
-	u32 table = cfg->fc_table;
 	int err;
 
 	if (nh->fib_nh_gw_family == AF_INET)
-		err = fib_check_nh_v4_gw(net, nh, table, cfg->fc_scope, extack);
+		err = fib_check_nh_v4_gw(net, nh, table, scope, extack);
 	else if (nh->fib_nh_gw_family == AF_INET6)
 		err = fib_check_nh_v6_gw(net, nh, table, extack);
 	else
@@ -1191,11 +1189,10 @@ static void fib_info_hash_move(struct hlist_head *new_info_hash,
 	fib_info_hash_free(old_laddrhash, bytes);
 }
 
-__be32 fib_info_update_nh_saddr(struct net *net, struct fib_nh *nh)
+__be32 fib_info_update_nh_saddr(struct net *net, struct fib_nh *nh,
+				unsigned char scope)
 {
-	nh->nh_saddr = inet_select_addr(nh->fib_nh_dev,
-					nh->fib_nh_gw4,
-					nh->nh_parent->fib_scope);
+	nh->nh_saddr = inet_select_addr(nh->fib_nh_dev, nh->fib_nh_gw4, scope);
 	nh->nh_saddr_genid = atomic_read(&net->ipv4.dev_addr_genid);
 
 	return nh->nh_saddr;
@@ -1213,7 +1210,7 @@ __be32 fib_result_prefsrc(struct net *net, struct fib_result *res)
 	if (nh->nh_saddr_genid == atomic_read(&net->ipv4.dev_addr_genid))
 		return nh->nh_saddr;
 
-	return fib_info_update_nh_saddr(net, nh);
+	return fib_info_update_nh_saddr(net, nh, res->fi->fib_scope);
 }
 
 static bool fib_valid_prefsrc(struct fib_config *cfg, __be32 fib_prefsrc)
@@ -1377,7 +1374,9 @@ struct fib_info *fib_create_info(struct fib_config *cfg,
 		int linkdown = 0;
 
 		change_nexthops(fi) {
-			err = fib_check_nh(cfg, nexthop_nh, extack);
+			err = fib_check_nh(cfg->fc_nlinfo.nl_net, nexthop_nh,
+					   cfg->fc_table, cfg->fc_scope,
+					   extack);
 			if (err != 0)
 				goto failure;
 			if (nexthop_nh->fib_nh_flags & RTNH_F_LINKDOWN)
@@ -1393,7 +1392,7 @@ struct fib_info *fib_create_info(struct fib_config *cfg,
 	}
 
 	change_nexthops(fi) {
-		fib_info_update_nh_saddr(net, nexthop_nh);
+		fib_info_update_nh_saddr(net, nexthop_nh, fi->fib_scope);
 		if (nexthop_nh->fib_nh_gw_family == AF_INET6)
 			fi->fib_nh_is_v6 = true;
 	} endfor_nexthops(fi)
@@ -1713,7 +1712,7 @@ static int call_fib_nh_notifiers(struct fib_nh *nh,
  * - if the new MTU is greater than the PMTU, don't make any change
  * - otherwise, unlock and set PMTU
  */
-static void nh_update_mtu(struct fib_nh_common *nhc, u32 new, u32 orig)
+void fib_nhc_update_mtu(struct fib_nh_common *nhc, u32 new, u32 orig)
 {
 	struct fnhe_hash_bucket *bucket;
 	int i;
@@ -1749,7 +1748,7 @@ void fib_sync_mtu(struct net_device *dev, u32 orig_mtu)
 
 	hlist_for_each_entry(nh, head, nh_hash) {
 		if (nh->fib_nh_dev == dev)
-			nh_update_mtu(&nh->nh_common, dev->mtu, orig_mtu);
+			fib_nhc_update_mtu(&nh->nh_common, dev->mtu, orig_mtu);
 	}
 }
 

net/ipv4/fib_trie.c

@@ -1943,6 +1943,78 @@ int fib_table_flush(struct net *net, struct fib_table *tb, bool flush_all)
 	return found;
 }
 
+/* derived from fib_trie_free */
+static void __fib_info_notify_update(struct net *net, struct fib_table *tb,
+				     struct nl_info *info)
+{
+	struct trie *t = (struct trie *)tb->tb_data;
+	struct key_vector *pn = t->kv;
+	unsigned long cindex = 1;
+	struct fib_alias *fa;
+
+	for (;;) {
+		struct key_vector *n;
+
+		if (!(cindex--)) {
+			t_key pkey = pn->key;
+
+			if (IS_TRIE(pn))
+				break;
+
+			n = pn;
+			pn = node_parent(pn);
+			cindex = get_index(pkey, pn);
+			continue;
+		}
+
+		/* grab the next available node */
+		n = get_child(pn, cindex);
+		if (!n)
+			continue;
+
+		if (IS_TNODE(n)) {
+			/* record pn and cindex for leaf walking */
+			pn = n;
+			cindex = 1ul << n->bits;
+
+			continue;
+		}
+
+		hlist_for_each_entry(fa, &n->leaf, fa_list) {
+			struct fib_info *fi = fa->fa_info;
+
+			if (!fi || !fi->nh_updated || fa->tb_id != tb->tb_id)
+				continue;
+
+			rtmsg_fib(RTM_NEWROUTE, htonl(n->key), fa,
+				  KEYLENGTH - fa->fa_slen, tb->tb_id,
+				  info, NLM_F_REPLACE);
+
+			/* call_fib_entry_notifiers will be removed when
+			 * in-kernel notifier is implemented and supported
+			 * for nexthop objects
+			 */
+			call_fib_entry_notifiers(net, FIB_EVENT_ENTRY_REPLACE,
+						 n->key,
+						 KEYLENGTH - fa->fa_slen, fa,
+						 NULL);
+		}
+	}
+}
+
+void fib_info_notify_update(struct net *net, struct nl_info *info)
+{
+	unsigned int h;
+
+	for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
+		struct hlist_head *head = &net->ipv4.fib_table_hash[h];
+		struct fib_table *tb;
+
+		hlist_for_each_entry_rcu(tb, head, tb_hlist)
+			__fib_info_notify_update(net, tb, info);
+	}
+}
+
 static void fib_leaf_notify(struct net *net, struct key_vector *l,
 			    struct fib_table *tb, struct notifier_block *nb)
 {

net/ipv6/addrconf_core.c

@@ -183,6 +183,11 @@ static int eafnosupport_fib6_nh_init(struct net *net, struct fib6_nh *fib6_nh,
 	return -EAFNOSUPPORT;
 }
 
+static int eafnosupport_ip6_del_rt(struct net *net, struct fib6_info *rt)
+{
+	return -EAFNOSUPPORT;
+}
+
 const struct ipv6_stub *ipv6_stub __read_mostly = &(struct ipv6_stub) {
 	.ipv6_dst_lookup   = eafnosupport_ipv6_dst_lookup,
 	.ipv6_route_input  = eafnosupport_ipv6_route_input,
@@ -192,6 +197,7 @@ const struct ipv6_stub *ipv6_stub __read_mostly = &(struct ipv6_stub) {
 	.fib6_select_path  = eafnosupport_fib6_select_path,
 	.ip6_mtu_from_fib6 = eafnosupport_ip6_mtu_from_fib6,
 	.fib6_nh_init	   = eafnosupport_fib6_nh_init,
+	.ip6_del_rt	   = eafnosupport_ip6_del_rt,
 };
 EXPORT_SYMBOL_GPL(ipv6_stub);
 

net/ipv6/af_inet6.c

@@ -926,6 +926,9 @@ static const struct ipv6_stub ipv6_stub_impl = {
 	.ip6_mtu_from_fib6 = ip6_mtu_from_fib6,
 	.fib6_nh_init	   = fib6_nh_init,
 	.fib6_nh_release   = fib6_nh_release,
+	.fib6_update_sernum = fib6_update_sernum_stub,
+	.fib6_rt_update	   = fib6_rt_update,
+	.ip6_del_rt	   = ip6_del_rt,
 	.udpv6_encap_enable = udpv6_encap_enable,
 	.ndisc_send_na = ndisc_send_na,
 	.nd_tbl	= &nd_tbl,

net/ipv6/ip6_fib.c

@@ -393,10 +393,10 @@ static int call_fib6_entry_notifier(struct notifier_block *nb, struct net *net,
 	return call_fib6_notifier(nb, net, event_type, &info.info);
 }
 
-static int call_fib6_entry_notifiers(struct net *net,
-				     enum fib_event_type event_type,
-				     struct fib6_info *rt,
-				     struct netlink_ext_ack *extack)
+int call_fib6_entry_notifiers(struct net *net,
+			      enum fib_event_type event_type,
+			      struct fib6_info *rt,
+			      struct netlink_ext_ack *extack)
 {
 	struct fib6_entry_notifier_info info = {
 		.info.extack = extack,
@@ -1222,6 +1222,14 @@ void fib6_update_sernum_upto_root(struct net *net, struct fib6_info *rt)
 	__fib6_update_sernum_upto_root(rt, fib6_new_sernum(net));
 }
 
+/* allow ipv4 to update sernum via ipv6_stub */
+void fib6_update_sernum_stub(struct net *net, struct fib6_info *f6i)
+{
+	spin_lock_bh(&f6i->fib6_table->tb6_lock);
+	fib6_update_sernum_upto_root(net, f6i);
+	spin_unlock_bh(&f6i->fib6_table->tb6_lock);
+}
+
 /*
  *	Add routing information to the routing tree.
  *	<destination addr>/<source addr>

net/ipv6/route.c

@@ -5123,6 +5123,38 @@ void inet6_rt_notify(int event, struct fib6_info *rt, struct nl_info *info,
 		rtnl_set_sk_err(net, RTNLGRP_IPV6_ROUTE, err);
 }
 
+void fib6_rt_update(struct net *net, struct fib6_info *rt,
+		    struct nl_info *info)
+{
+	u32 seq = info->nlh ? info->nlh->nlmsg_seq : 0;
+	struct sk_buff *skb;
+	int err = -ENOBUFS;
+
+	/* call_fib6_entry_notifiers will be removed when in-kernel notifier
+	 * is implemented and supported for nexthop objects
+	 */
+	call_fib6_entry_notifiers(net, FIB_EVENT_ENTRY_REPLACE, rt, NULL);
+
+	skb = nlmsg_new(rt6_nlmsg_size(rt), gfp_any());
+	if (!skb)
+		goto errout;
+
+	err = rt6_fill_node(net, skb, rt, NULL, NULL, NULL, 0,
+			    RTM_NEWROUTE, info->portid, seq, NLM_F_REPLACE);
+	if (err < 0) {
+		/* -EMSGSIZE implies BUG in rt6_nlmsg_size() */
+		WARN_ON(err == -EMSGSIZE);
+		kfree_skb(skb);
+		goto errout;
+	}
+	rtnl_notify(skb, net, info->portid, RTNLGRP_IPV6_ROUTE,
+		    info->nlh, gfp_any());
+	return;
+errout:
+	if (err < 0)
+		rtnl_set_sk_err(net, RTNLGRP_IPV6_ROUTE, err);
+}
+
 static int ip6_route_dev_notify(struct notifier_block *this,
 				unsigned long event, void *ptr)
 {