Merge branch 'ipv4-nexthop-Various-improvements'

Ido Schimmel says:

====================
ipv4: nexthop: Various improvements

This patch set contains various improvements that I made to the nexthop
object code while studying it towards my upcoming changes.

While patches #4 and #6 fix bugs, they are not regressions (never
worked). They also do not occur to me as critical issues, which is why I
am targeting them at net-next.

Tested with fib_nexthops.sh:

Tests passed: 134
Tests failed:   0
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 72 insertions, 7 deletions

diff --git a/net/ipv4/nexthop.c b/net/ipv4/nexthop.c
index 134e92382275..bf9d4cd2d6e5 100644
--- a/net/ipv4/nexthop.c
+++ b/net/ipv4/nexthop.c
@@ -133,12 +133,9 @@ static struct nexthop *nexthop_alloc(void)
 
 static struct nh_group *nexthop_grp_alloc(u16 num_nh)
 {
-	size_t sz = offsetof(struct nexthop, nh_grp)
-		    + sizeof(struct nh_group)
-		    + sizeof(struct nh_grp_entry) * num_nh;
 	struct nh_group *nhg;
 
-	nhg = kzalloc(sz, GFP_KERNEL);
+	nhg = kzalloc(struct_size(nhg, nh_entries, num_nh), GFP_KERNEL);
 	if (nhg)
 		nhg->num_nh = num_nh;
 
@@ -279,7 +276,7 @@ static int nh_fill_node(struct sk_buff *skb, struct nexthop *nh,
 	case AF_INET:
 		fib_nh = &nhi->fib_nh;
 		if (fib_nh->fib_nh_gw_family &&
-		    nla_put_u32(skb, NHA_GATEWAY, fib_nh->fib_nh_gw4))
+		    nla_put_be32(skb, NHA_GATEWAY, fib_nh->fib_nh_gw4))
 			goto nla_put_failure;
 		break;
 
@@ -800,7 +797,7 @@ static void remove_nh_grp_entry(struct net *net, struct nh_grp_entry *nhge,
 		return;
 	}
 
-	newg->has_v4 = nhg->has_v4;
+	newg->has_v4 = false;
 	newg->mpath = nhg->mpath;
 	newg->fdb_nh = nhg->fdb_nh;
 	newg->num_nh = nhg->num_nh;
@@ -809,12 +806,18 @@ static void remove_nh_grp_entry(struct net *net, struct nh_grp_entry *nhge,
 	nhges = nhg->nh_entries;
 	new_nhges = newg->nh_entries;
 	for (i = 0, j = 0; i < nhg->num_nh; ++i) {
+		struct nh_info *nhi;
+
 		/* current nexthop getting removed */
 		if (nhg->nh_entries[i].nh == nh) {
 			newg->num_nh--;
 			continue;
 		}
 
+		nhi = rtnl_dereference(nhges[i].nh->nh_info);
+		if (nhi->family == AF_INET)
+			newg->has_v4 = true;
+
 		list_del(&nhges[i].nh_list);
 		new_nhges[j].nh_parent = nhges[i].nh_parent;
 		new_nhges[j].nh = nhges[i].nh;
@@ -961,6 +964,23 @@ static int replace_nexthop_grp(struct net *net, struct nexthop *old,
 	return 0;
 }
 
+static void nh_group_v4_update(struct nh_group *nhg)
+{
+	struct nh_grp_entry *nhges;
+	bool has_v4 = false;
+	int i;
+
+	nhges = nhg->nh_entries;
+	for (i = 0; i < nhg->num_nh; i++) {
+		struct nh_info *nhi;
+
+		nhi = rtnl_dereference(nhges[i].nh->nh_info);
+		if (nhi->family == AF_INET)
+			has_v4 = true;
+	}
+	nhg->has_v4 = has_v4;
+}
+
 static int replace_nexthop_single(struct net *net, struct nexthop *old,
 				  struct nexthop *new,
 				  struct netlink_ext_ack *extack)
@@ -984,6 +1004,21 @@ static int replace_nexthop_single(struct net *net, struct nexthop *old,
 	rcu_assign_pointer(old->nh_info, newi);
 	rcu_assign_pointer(new->nh_info, oldi);
 
+	/* When replacing an IPv4 nexthop with an IPv6 nexthop, potentially
+	 * update IPv4 indication in all the groups using the nexthop.
+	 */
+	if (oldi->family == AF_INET && newi->family == AF_INET6) {
+		struct nh_grp_entry *nhge;
+
+		list_for_each_entry(nhge, &old->grp_list, nh_list) {
+			struct nexthop *nhp = nhge->nh_parent;
+			struct nh_group *nhg;
+
+			nhg = rtnl_dereference(nhp->nh_grp);
+			nh_group_v4_update(nhg);
+		}
+	}
+
 	return 0;
 }
 
@@ -1101,7 +1136,7 @@ static int insert_nexthop(struct net *net, struct nexthop *new_nh,
 	while (1) {
 		struct nexthop *nh;
 
-		next = rtnl_dereference(*pp);
+		next = *pp;
 		if (!next)
 			break;
 
diff --git a/tools/testing/selftests/net/fib_nexthops.sh b/tools/testing/selftests/net/fib_nexthops.sh
index 22dc2f3d428b..b74884d52913 100755
--- a/tools/testing/selftests/net/fib_nexthops.sh
+++ b/tools/testing/selftests/net/fib_nexthops.sh
@@ -739,6 +739,36 @@ ipv6_fcnal_runtime()
 	run_cmd "$IP nexthop replace id 81 via 172.16.1.1 dev veth1"
 	log_test $? 2 "Nexthop replace of group entry - v6 route, v4 nexthop"
 
+	run_cmd "$IP nexthop add id 86 via 2001:db8:92::2 dev veth3"
+	run_cmd "$IP nexthop add id 87 via 172.16.1.1 dev veth1"
+	run_cmd "$IP nexthop add id 88 via 172.16.1.1 dev veth1"
+	run_cmd "$IP nexthop add id 124 group 86/87/88"
+	run_cmd "$IP ro replace 2001:db8:101::1/128 nhid 124"
+	log_test $? 2 "IPv6 route can not have a group with v4 and v6 gateways"
+
+	run_cmd "$IP nexthop del id 88"
+	run_cmd "$IP ro replace 2001:db8:101::1/128 nhid 124"
+	log_test $? 2 "IPv6 route can not have a group with v4 and v6 gateways"
+
+	run_cmd "$IP nexthop del id 87"
+	run_cmd "$IP ro replace 2001:db8:101::1/128 nhid 124"
+	log_test $? 0 "IPv6 route using a group after removing v4 gateways"
+
+	run_cmd "$IP ro delete 2001:db8:101::1/128"
+	run_cmd "$IP nexthop add id 87 via 172.16.1.1 dev veth1"
+	run_cmd "$IP nexthop add id 88 via 172.16.1.1 dev veth1"
+	run_cmd "$IP nexthop replace id 124 group 86/87/88"
+	run_cmd "$IP ro replace 2001:db8:101::1/128 nhid 124"
+	log_test $? 2 "IPv6 route can not have a group with v4 and v6 gateways"
+
+	run_cmd "$IP nexthop replace id 88 via 2001:db8:92::2 dev veth3"
+	run_cmd "$IP ro replace 2001:db8:101::1/128 nhid 124"
+	log_test $? 2 "IPv6 route can not have a group with v4 and v6 gateways"
+
+	run_cmd "$IP nexthop replace id 87 via 2001:db8:92::2 dev veth3"
+	run_cmd "$IP ro replace 2001:db8:101::1/128 nhid 124"
+	log_test $? 0 "IPv6 route using a group after replacing v4 gateways"
+
 	$IP nexthop flush >/dev/null 2>&1
 
 	#