ipv4: Change fib_nexthop_info and fib_add_nexthop to take fib_nh_common

With the exception of the nexthop weight, the nexthop attributes used by
fib_nexthop_info and fib_add_nexthop come from the fib_nh_common struct.
Update both to use it and change fib_nexthop_info to check the family
as needed.

nexthop weight comes from the common struct for existing use cases, but
for nexthop groups the weight is outside of the fib_nh_common to allow
the same nexthop definition to be used in multiple groups with different
weights.
Signed-off-by: David Ahern <dsahern@gmail.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv4/fib_semantics.c

@@ -1317,35 +1317,44 @@ struct fib_info *fib_create_info(struct fib_config *cfg,
 	return ERR_PTR(err);
 }
 
-static int fib_nexthop_info(struct sk_buff *skb, const struct fib_nh *nh,
+static int fib_nexthop_info(struct sk_buff *skb, const struct fib_nh_common *nhc,
 			    unsigned int *flags, bool skip_oif)
 {
-	if (nh->fib_nh_flags & RTNH_F_DEAD)
+	if (nhc->nhc_flags & RTNH_F_DEAD)
 		*flags |= RTNH_F_DEAD;
 
-	if (nh->fib_nh_flags & RTNH_F_LINKDOWN) {
+	if (nhc->nhc_flags & RTNH_F_LINKDOWN) {
 		*flags |= RTNH_F_LINKDOWN;
 
 		rcu_read_lock();
-		if (ip_ignore_linkdown(nh->fib_nh_dev))
+		switch (nhc->nhc_family) {
+		case AF_INET:
+			if (ip_ignore_linkdown(nhc->nhc_dev))
 				*flags |= RTNH_F_DEAD;
+			break;
+		}
 		rcu_read_unlock();
 	}
 
-	if (nh->fib_nh_gw4 &&
-	    nla_put_in_addr(skb, RTA_GATEWAY, nh->fib_nh_gw4))
+	if (nhc->nhc_has_gw) {
+		switch (nhc->nhc_family) {
+		case AF_INET:
+			if (nla_put_in_addr(skb, RTA_GATEWAY, nhc->nhc_gw.ipv4))
 				goto nla_put_failure;
+			break;
+		}
+	}
 
-	*flags |= (nh->fib_nh_flags & RTNH_F_ONLINK);
-	if (nh->fib_nh_flags & RTNH_F_OFFLOAD)
+	*flags |= (nhc->nhc_flags & RTNH_F_ONLINK);
+	if (nhc->nhc_flags & RTNH_F_OFFLOAD)
 		*flags |= RTNH_F_OFFLOAD;
 
-	if (!skip_oif && nh->fib_nh_dev &&
-	    nla_put_u32(skb, RTA_OIF, nh->fib_nh_dev->ifindex))
+	if (!skip_oif && nhc->nhc_dev &&
+	    nla_put_u32(skb, RTA_OIF, nhc->nhc_dev->ifindex))
 		goto nla_put_failure;
 
-	if (nh->fib_nh_lws &&
-	    lwtunnel_fill_encap(skb, nh->fib_nh_lws) < 0)
+	if (nhc->nhc_lwtstate &&
+	    lwtunnel_fill_encap(skb, nhc->nhc_lwtstate) < 0)
 		goto nla_put_failure;
 
 	return 0;
@@ -1355,9 +1364,10 @@ static int fib_nexthop_info(struct sk_buff *skb, const struct fib_nh *nh,
 }
 
 #ifdef CONFIG_IP_ROUTE_MULTIPATH
-static int fib_add_nexthop(struct sk_buff *skb, const struct fib_nh *nh)
+static int fib_add_nexthop(struct sk_buff *skb, const struct fib_nh_common *nhc,
+			   int nh_weight)
 {
-	const struct net_device *dev = nh->fib_nh_dev;
+	const struct net_device *dev = nhc->nhc_dev;
 	struct rtnexthop *rtnh;
 	unsigned int flags = 0;
 
@@ -1365,10 +1375,10 @@ static int fib_add_nexthop(struct sk_buff *skb, const struct fib_nh *nh)
 	if (!rtnh)
 		goto nla_put_failure;
 
-	rtnh->rtnh_hops = nh->fib_nh_weight - 1;
+	rtnh->rtnh_hops = nh_weight - 1;
 	rtnh->rtnh_ifindex = dev ? dev->ifindex : 0;
 
-	if (fib_nexthop_info(skb, nh, &flags, true) < 0)
+	if (fib_nexthop_info(skb, nhc, &flags, true) < 0)
 		goto nla_put_failure;
 
 	rtnh->rtnh_flags = flags;
@@ -1381,7 +1391,9 @@ static int fib_add_nexthop(struct sk_buff *skb, const struct fib_nh *nh)
 nla_put_failure:
 	return -EMSGSIZE;
 }
+#endif
 
+#ifdef CONFIG_IP_ROUTE_MULTIPATH
 static int fib_add_multipath(struct sk_buff *skb, struct fib_info *fi)
 {
 	struct nlattr *mp;
@@ -1391,7 +1403,7 @@ static int fib_add_multipath(struct sk_buff *skb, struct fib_info *fi)
 		goto nla_put_failure;
 
 	for_nexthops(fi) {
-		if (fib_add_nexthop(skb, nh) < 0)
+		if (fib_add_nexthop(skb, &nh->nh_common, nh->fib_nh_weight) < 0)
 			goto nla_put_failure;
 #ifdef CONFIG_IP_ROUTE_CLASSID
 		if (nh->nh_tclassid &&
@@ -1457,7 +1469,7 @@ int fib_dump_info(struct sk_buff *skb, u32 portid, u32 seq, int event,
 		struct fib_nh *nh = &fi->fib_nh[0];
 		unsigned int flags = 0;
 
-		if (fib_nexthop_info(skb, nh, &flags, false) < 0)
+		if (fib_nexthop_info(skb, &nh->nh_common, &flags, false) < 0)
 			goto nla_put_failure;
 
 		rtm->rtm_flags = flags;