ipv6: Flip to fib_nexthop_info

Export fib_nexthop_info and fib_add_nexthop for use by IPv6 code.
Remove rt6_nexthop_info and rt6_add_nexthop in favor of the IPv4
versions. Update fib_nexthop_info for IPv6 linkdown check and
RTA_GATEWAY for AF_INET6.
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>

include/net/ip_fib.h

@@ -492,4 +492,9 @@ u32 ip_mtu_from_fib_result(struct fib_result *res, __be32 daddr);
 int ip_valid_fib_dump_req(struct net *net, const struct nlmsghdr *nlh,
 			  struct fib_dump_filter *filter,
 			  struct netlink_callback *cb);
+
+int fib_nexthop_info(struct sk_buff *skb, const struct fib_nh_common *nh,
+		     unsigned int *flags, bool skip_oif);
+int fib_add_nexthop(struct sk_buff *skb, const struct fib_nh_common *nh,
+		    int nh_weight);
 #endif  /* _NET_FIB_H */

net/ipv4/fib_semantics.c

@@ -45,6 +45,7 @@
 #include <net/nexthop.h>
 #include <net/lwtunnel.h>
 #include <net/fib_notifier.h>
+#include <net/addrconf.h>
 
 #include "fib_lookup.h"
 
@@ -1317,7 +1318,7 @@ 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_common *nhc,
+int fib_nexthop_info(struct sk_buff *skb, const struct fib_nh_common *nhc,
 		     unsigned int *flags, bool skip_oif)
 {
 	if (nhc->nhc_flags & RTNH_F_DEAD)
@@ -1332,6 +1333,10 @@ static int fib_nexthop_info(struct sk_buff *skb, const struct fib_nh_common *nhc
 			if (ip_ignore_linkdown(nhc->nhc_dev))
 				*flags |= RTNH_F_DEAD;
 			break;
+		case AF_INET6:
+			if (ip6_ignore_linkdown(nhc->nhc_dev))
+				*flags |= RTNH_F_DEAD;
+			break;
 		}
 		rcu_read_unlock();
 	}
@@ -1342,6 +1347,11 @@ static int fib_nexthop_info(struct sk_buff *skb, const struct fib_nh_common *nhc
 			if (nla_put_in_addr(skb, RTA_GATEWAY, nhc->nhc_gw.ipv4))
 				goto nla_put_failure;
 			break;
+		case AF_INET6:
+			if (nla_put_in6_addr(skb, RTA_GATEWAY,
+					     &nhc->nhc_gw.ipv6) < 0)
+				goto nla_put_failure;
+			break;
 		}
 	}
 
@@ -1362,9 +1372,10 @@ static int fib_nexthop_info(struct sk_buff *skb, const struct fib_nh_common *nhc
 nla_put_failure:
 	return -EMSGSIZE;
 }
+EXPORT_SYMBOL_GPL(fib_nexthop_info);
 
-#ifdef CONFIG_IP_ROUTE_MULTIPATH
-static int fib_add_nexthop(struct sk_buff *skb, const struct fib_nh_common *nhc,
+#if IS_ENABLED(CONFIG_IP_ROUTE_MULTIPATH) || IS_ENABLED(CONFIG_IPV6)
+int fib_add_nexthop(struct sk_buff *skb, const struct fib_nh_common *nhc,
 		    int nh_weight)
 {
 	const struct net_device *dev = nhc->nhc_dev;
@@ -1391,6 +1402,7 @@ static int fib_add_nexthop(struct sk_buff *skb, const struct fib_nh_common *nhc,
 nla_put_failure:
 	return -EMSGSIZE;
 }
+EXPORT_SYMBOL_GPL(fib_add_nexthop);
 #endif
 
 #ifdef CONFIG_IP_ROUTE_MULTIPATH

net/ipv6/route.c

@@ -4582,73 +4582,6 @@ static size_t rt6_nlmsg_size(struct fib6_info *rt)
 	       + nexthop_len;
 }
 
-static int rt6_nexthop_info(struct sk_buff *skb, const struct fib6_nh *fib6_nh,
-			    unsigned int *flags, bool skip_oif)
-{
-	if (fib6_nh->fib_nh_flags & RTNH_F_DEAD)
-		*flags |= RTNH_F_DEAD;
-
-	if (fib6_nh->fib_nh_flags & RTNH_F_LINKDOWN) {
-		*flags |= RTNH_F_LINKDOWN;
-
-		rcu_read_lock();
-		if (ip6_ignore_linkdown(fib6_nh->fib_nh_dev))
-			*flags |= RTNH_F_DEAD;
-		rcu_read_unlock();
-	}
-
-	if (fib6_nh->fib_nh_has_gw) {
-		if (nla_put_in6_addr(skb, RTA_GATEWAY, &fib6_nh->fib_nh_gw6) < 0)
-			goto nla_put_failure;
-	}
-
-	*flags |= (fib6_nh->fib_nh_flags & RTNH_F_ONLINK);
-	if (fib6_nh->fib_nh_flags & RTNH_F_OFFLOAD)
-		*flags |= RTNH_F_OFFLOAD;
-
-	/* not needed for multipath encoding b/c it has a rtnexthop struct */
-	if (!skip_oif && fib6_nh->fib_nh_dev &&
-	    nla_put_u32(skb, RTA_OIF, fib6_nh->fib_nh_dev->ifindex))
-		goto nla_put_failure;
-
-	if (fib6_nh->fib_nh_lws &&
-	    lwtunnel_fill_encap(skb, fib6_nh->fib_nh_lws) < 0)
-		goto nla_put_failure;
-
-	return 0;
-
-nla_put_failure:
-	return -EMSGSIZE;
-}
-
-/* add multipath next hop */
-static int rt6_add_nexthop(struct sk_buff *skb, const struct fib6_nh *fib6_nh)
-{
-	const struct net_device *dev = fib6_nh->fib_nh_dev;
-	struct rtnexthop *rtnh;
-	unsigned int flags = 0;
-
-	rtnh = nla_reserve_nohdr(skb, sizeof(*rtnh));
-	if (!rtnh)
-		goto nla_put_failure;
-
-	rtnh->rtnh_hops = fib6_nh->fib_nh_weight - 1;
-	rtnh->rtnh_ifindex = dev ? dev->ifindex : 0;
-
-	if (rt6_nexthop_info(skb, fib6_nh, &flags, true) < 0)
-		goto nla_put_failure;
-
-	rtnh->rtnh_flags = flags;
-
-	/* length of rtnetlink header + attributes */
-	rtnh->rtnh_len = nlmsg_get_pos(skb) - (void *)rtnh;
-
-	return 0;
-
-nla_put_failure:
-	return -EMSGSIZE;
-}
-
 static int rt6_fill_node(struct net *net, struct sk_buff *skb,
 			 struct fib6_info *rt, struct dst_entry *dst,
 			 struct in6_addr *dest, struct in6_addr *src,
@@ -4765,19 +4698,21 @@ static int rt6_fill_node(struct net *net, struct sk_buff *skb,
 		if (!mp)
 			goto nla_put_failure;
 
-		if (rt6_add_nexthop(skb, &rt->fib6_nh) < 0)
+		if (fib_add_nexthop(skb, &rt->fib6_nh.nh_common,
+				    rt->fib6_nh.fib_nh_weight) < 0)
 			goto nla_put_failure;
 
 		list_for_each_entry_safe(sibling, next_sibling,
 					 &rt->fib6_siblings, fib6_siblings) {
-			if (rt6_add_nexthop(skb, &sibling->fib6_nh) < 0)
+			if (fib_add_nexthop(skb, &sibling->fib6_nh.nh_common,
+					    sibling->fib6_nh.fib_nh_weight) < 0)
 				goto nla_put_failure;
 		}
 
 		nla_nest_end(skb, mp);
 	} else {
-		if (rt6_nexthop_info(skb, &rt->fib6_nh, &rtm->rtm_flags,
-				     false) < 0)
+		if (fib_nexthop_info(skb, &rt->fib6_nh.nh_common,
+				     &rtm->rtm_flags, false) < 0)
 			goto nla_put_failure;
 	}