[PATCH net-next 0/7] net: Export functions for nexthop code

[PATCH net-next 0/7] net: Export functions for nexthop code

[David Ahern]

From: David Ahern <dsahern@gmail.com>

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.

David Ahern (7):
  ipv6: Add delete route hook to stubs
  ipv6: Add hook to bump sernum for a route to stubs
  ipv6: export function to send route updates
  ipv4: Add function to send route updates
  ipv4: export fib_check_nh
  ipv4: export fib_flush
  ipv4: export fib_info_update_nh_saddr

 include/net/ip6_fib.h    |  7 +++++
 include/net/ip_fib.h     |  8 +++++-
 include/net/ipv6_stubs.h |  5 ++++
 net/ipv4/fib_frontend.c  |  2 +-
 net/ipv4/fib_semantics.c | 23 ++++++++--------
 net/ipv4/fib_trie.c      | 72 ++++++++++++++++++++++++++++++++++++++++++++++++
 net/ipv6/addrconf_core.c |  6 ++++
 net/ipv6/af_inet6.c      |  3 ++
 net/ipv6/ip6_fib.c       | 16 ++++++++---
 net/ipv6/route.c         | 32 +++++++++++++++++++++
 10 files changed, 156 insertions(+), 18 deletions(-)

-- 
2.11.0

[PATCH net-next 1/7] ipv6: Add delete route hook to stubs

[David Ahern]

From: David Ahern <dsahern@gmail.com>

Add ip6_del_rt to the IPv6 stub. The hook is needed by the nexthop
code to remove entries linked to a nexthop that is getting deleted.

Signed-off-by: David Ahern <dsahern@gmail.com>
---
 include/net/ipv6_stubs.h | 1 +
 net/ipv6/addrconf_core.c | 6 ++++++
 net/ipv6/af_inet6.c      | 1 +
 3 files changed, 8 insertions(+)

diff --git a/include/net/ipv6_stubs.h b/include/net/ipv6_stubs.h
index 6c0c4fde16f8..307114a46eee 100644
--- a/include/net/ipv6_stubs.h
+++ b/include/net/ipv6_stubs.h
@@ -45,6 +45,7 @@ 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);
+	int (*ip6_del_rt)(struct net *net, struct fib6_info *rt);
 	void (*udpv6_encap_enable)(void);
 	void (*ndisc_send_na)(struct net_device *dev, const struct in6_addr *daddr,
 			      const struct in6_addr *solicited_addr,
diff --git a/net/ipv6/addrconf_core.c b/net/ipv6/addrconf_core.c
index 763a947e0d14..9644af96810d 100644
--- a/net/ipv6/addrconf_core.c
+++ b/net/ipv6/addrconf_core.c
@@ -182,6 +182,11 @@ 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,
@@ -191,6 +196,7 @@ 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);
 
diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c
index c04ae282f4e4..bc2ca61a020a 100644
--- a/net/ipv6/af_inet6.c
+++ b/net/ipv6/af_inet6.c
@@ -926,6 +926,7 @@ 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,
+	.ip6_del_rt	   = ip6_del_rt,
 	.udpv6_encap_enable = udpv6_encap_enable,
 	.ndisc_send_na = ndisc_send_na,
 	.nd_tbl	= &nd_tbl,
-- 
2.11.0

[PATCH net-next 2/7] ipv6: Add hook to bump sernum for a route to stubs

[David Ahern]

From: David Ahern <dsahern@gmail.com>

Add hook to ipv6 stub to bump the sernum up to the root node for a
route. This is needed by the nexthop code when a nexthop config changes.

Signed-off-by: David Ahern <dsahern@gmail.com>
---
 include/net/ip6_fib.h    | 1 +
 include/net/ipv6_stubs.h | 1 +
 net/ipv6/af_inet6.c      | 1 +
 net/ipv6/ip6_fib.c       | 8 ++++++++
 4 files changed, 11 insertions(+)

diff --git a/include/net/ip6_fib.h b/include/net/ip6_fib.h
index 40105738e2f6..d1f1f94e0267 100644
--- a/include/net/ip6_fib.h
+++ b/include/net/ip6_fib.h
@@ -484,6 +484,7 @@ 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)
diff --git a/include/net/ipv6_stubs.h b/include/net/ipv6_stubs.h
index 307114a46eee..97f42e16b3b3 100644
--- a/include/net/ipv6_stubs.h
+++ b/include/net/ipv6_stubs.h
@@ -45,6 +45,7 @@ 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 (*udpv6_encap_enable)(void);
 	void (*ndisc_send_na)(struct net_device *dev, const struct in6_addr *daddr,
diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c
index bc2ca61a020a..55138f0d2b9d 100644
--- a/net/ipv6/af_inet6.c
+++ b/net/ipv6/af_inet6.c
@@ -926,6 +926,7 @@ 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,
 	.ip6_del_rt	   = ip6_del_rt,
 	.udpv6_encap_enable = udpv6_encap_enable,
 	.ndisc_send_na = ndisc_send_na,
diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c
index 08e0390e001c..c333a9710034 100644
--- a/net/ipv6/ip6_fib.c
+++ b/net/ipv6/ip6_fib.c
@@ -1216,6 +1216,14 @@ 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>
-- 
2.11.0

[PATCH net-next 3/7] ipv6: export function to send route updates

[David Ahern]

From: David Ahern <dsahern@gmail.com>

Add fib6_rt_update to send RTM_NEWROUTE with NLM_F_REPLACE set. This
helper will be used by the nexthop code to notify userspace of routes
that are impacted when a nexthop config is updated via replace.

This notification is needed for legacy apps that do not understand
the new nexthop object. Apps that are nexthop aware can use the
RTA_NH_ID attribute in the route notification to just ignore it.

In the future this should be wrapped in a sysctl to allow OS'es that
are fully updated to avoid the notificaton storm.

Signed-off-by: David Ahern <dsahern@gmail.com>
---
 include/net/ip6_fib.h    |  6 ++++++
 include/net/ipv6_stubs.h |  3 +++
 net/ipv6/af_inet6.c      |  1 +
 net/ipv6/ip6_fib.c       |  8 ++++----
 net/ipv6/route.c         | 32 ++++++++++++++++++++++++++++++++
 5 files changed, 46 insertions(+), 4 deletions(-)

diff --git a/include/net/ip6_fib.h b/include/net/ip6_fib.h
index d1f1f94e0267..296939183bdb 100644
--- a/include/net/ip6_fib.h
+++ b/include/net/ip6_fib.h
@@ -451,6 +451,12 @@ 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);
 
diff --git a/include/net/ipv6_stubs.h b/include/net/ipv6_stubs.h
index 97f42e16b3b3..5c93e942c50b 100644
--- a/include/net/ipv6_stubs.h
+++ b/include/net/ipv6_stubs.h
@@ -47,6 +47,9 @@ struct ipv6_stub {
 	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,
diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c
index 55138f0d2b9d..cc6f8d0c625a 100644
--- a/net/ipv6/af_inet6.c
+++ b/net/ipv6/af_inet6.c
@@ -927,6 +927,7 @@ static const struct ipv6_stub ipv6_stub_impl = {
 	.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,
diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c
index c333a9710034..305a5ed0f8d8 100644
--- a/net/ipv6/ip6_fib.c
+++ b/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,
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 23a20d62daac..e737b4fb61af 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -5113,6 +5113,38 @@ 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)
 {
-- 
2.11.0

[PATCH net-next 4/7] ipv4: Add function to send route updates

[David Ahern]

From: David Ahern <dsahern@gmail.com>

Add fib_info_notify_update to walk the fib and send RTM_NEWROUTE
notifications with NLM_F_REPLACE set for entries linked to a fib_info
that have nh_updated flag set. This helper will be used by the nexthop
code to notify userspace of routes that are impacted when a nexthop
config is updated via replace. The new function and its helper are
similar to how fib_flush and fib_table_flush work for address delete
and link down events.

This notification is needed for legacy apps that do not understand
the new nexthop object. Apps that are nexthop aware can use the
RTA_NH_ID attribute in the route notification to just ignore it.

In the future this should be wrapped in a sysctl to allow OS'es that
are fully updated to avoid the notificaton storm.

Signed-off-by: David Ahern <dsahern@gmail.com>
---
 include/net/ip_fib.h |  2 ++
 net/ipv4/fib_trie.c  | 72 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 74 insertions(+)

diff --git a/include/net/ip_fib.h b/include/net/ip_fib.h
index d0e28f4ab099..ec6496c08f48 100644
--- a/include/net/ip_fib.h
+++ b/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
@@ -231,6 +232,7 @@ 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 {
diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c
index 334f723bdf80..ea7df7ebf597 100644
--- a/net/ipv4/fib_trie.c
+++ b/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)
 {
-- 
2.11.0

[PATCH net-next 5/7] ipv4: export fib_check_nh

[David Ahern]

From: David Ahern <dsahern@gmail.com>

Change fib_check_nh to take net, table and scope as input arguments
over struct fib_config and export for use by nexthop code.

Signed-off-by: David Ahern <dsahern@gmail.com>
---
 include/net/ip_fib.h     |  2 ++
 net/ipv4/fib_semantics.c | 12 ++++++------
 2 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/include/net/ip_fib.h b/include/net/ip_fib.h
index ec6496c08f48..27d7c89ca9c4 100644
--- a/include/net/ip_fib.h
+++ b/include/net/ip_fib.h
@@ -436,6 +436,8 @@ void fib_sync_mtu(struct net_device *dev, u32 orig_mtu);
 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);
diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c
index d3da6a10f86f..4541121426fb 100644
--- a/net/ipv4/fib_semantics.c
+++ b/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
@@ -1377,7 +1375,9 @@ 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)
-- 
2.11.0

[PATCH net-next 6/7] ipv4: export fib_flush

[David Ahern]

From: David Ahern <dsahern@gmail.com>

As nexthops are deleted, fib entries referencing it are marked dead.
Export fib_flush so those entries can be removed in a timely manner.

Signed-off-by: David Ahern <dsahern@gmail.com>
---
 include/net/ip_fib.h    | 1 +
 net/ipv4/fib_frontend.c | 2 +-
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/include/net/ip_fib.h b/include/net/ip_fib.h
index 27d7c89ca9c4..79c18bd6a059 100644
--- a/include/net/ip_fib.h
+++ b/include/net/ip_fib.h
@@ -473,6 +473,7 @@ 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)
diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c
index b298255f6fdb..dfa57a84ac14 100644
--- a/net/ipv4/fib_frontend.c
+++ b/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;
-- 
2.11.0

[PATCH net-next 7/7] ipv4: export fib_info_update_nh_saddr

[David Ahern]

From: David Ahern <dsahern@gmail.com>

Add scope as input argument versus relying on fib_info reference in
fib_nh, and export fib_info_update_nh_saddr.

Signed-off-by: David Ahern <dsahern@gmail.com>
---
 include/net/ip_fib.h     |  3 ++-
 net/ipv4/fib_semantics.c | 11 +++++------
 2 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/include/net/ip_fib.h b/include/net/ip_fib.h
index 79c18bd6a059..8511ebb6f7be 100644
--- a/include/net/ip_fib.h
+++ b/include/net/ip_fib.h
@@ -201,7 +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)
diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c
index 4541121426fb..bd8c51d2c59b 100644
--- a/net/ipv4/fib_semantics.c
+++ b/net/ipv4/fib_semantics.c
@@ -1189,11 +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;
@@ -1211,7 +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)
@@ -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)
-- 
2.11.0

Re: [PATCH net-next 0/7] net: Export functions for nexthop code

[David Miller]

From: David Ahern <dsahern@kernel.org>
Date: Sun,  5 May 2019 09:40:49 -0700

> From: David Ahern <dsahern@gmail.com>
> 
> 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.

Since net-next is closed and you cannot therefore build upon this, I am not
applying this series.

Thanks.