1 files changed, 268 insertions, 96 deletions

diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c
index bfa49a88d03a..2db089e10ba0 100644
--- a/net/ipv4/fib_semantics.c
+++ b/net/ipv4/fib_semantics.c
@@ -38,6 +38,7 @@
 #include <net/sock.h>
 #include <net/ip_fib.h>
 #include <net/ip6_fib.h>
+#include <net/nexthop.h>
 #include <net/netlink.h>
 #include <net/rtnh.h>
 #include <net/lwtunnel.h>
@@ -56,18 +57,21 @@ static unsigned int fib_info_cnt;
 #define DEVINDEX_HASHSIZE (1U << DEVINDEX_HASHBITS)
 static struct hlist_head fib_info_devhash[DEVINDEX_HASHSIZE];
 
+/* for_nexthops and change_nexthops only used when nexthop object
+ * is not set in a fib_info. The logic within can reference fib_nh.
+ */
 #ifdef CONFIG_IP_ROUTE_MULTIPATH
 
 #define for_nexthops(fi) {						\
 	int nhsel; const struct fib_nh *nh;				\
 	for (nhsel = 0, nh = (fi)->fib_nh;				\
-	     nhsel < (fi)->fib_nhs;					\
+	     nhsel < fib_info_num_path((fi));				\
 	     nh++, nhsel++)
 
 #define change_nexthops(fi) {						\
 	int nhsel; struct fib_nh *nexthop_nh;				\
 	for (nhsel = 0,	nexthop_nh = (struct fib_nh *)((fi)->fib_nh);	\
-	     nhsel < (fi)->fib_nhs;					\
+	     nhsel < fib_info_num_path((fi));				\
 	     nexthop_nh++, nhsel++)
 
 #else /* CONFIG_IP_ROUTE_MULTIPATH */
@@ -228,9 +232,13 @@ static void free_fib_info_rcu(struct rcu_head *head)
 {
 	struct fib_info *fi = container_of(head, struct fib_info, rcu);
 
-	change_nexthops(fi) {
-		fib_nh_release(fi->fib_net, nexthop_nh);
-	} endfor_nexthops(fi);
+	if (fi->nh) {
+		nexthop_put(fi->nh);
+	} else {
+		change_nexthops(fi) {
+			fib_nh_release(fi->fib_net, nexthop_nh);
+		} endfor_nexthops(fi);
+	}
 
 	ip_fib_metrics_put(fi->fib_metrics);
 
@@ -256,22 +264,34 @@ void fib_release_info(struct fib_info *fi)
 		hlist_del(&fi->fib_hash);
 		if (fi->fib_prefsrc)
 			hlist_del(&fi->fib_lhash);
-		change_nexthops(fi) {
-			if (!nexthop_nh->fib_nh_dev)
-				continue;
-			hlist_del(&nexthop_nh->nh_hash);
-		} endfor_nexthops(fi)
+		if (fi->nh) {
+			list_del(&fi->nh_list);
+		} else {
+			change_nexthops(fi) {
+				if (!nexthop_nh->fib_nh_dev)
+					continue;
+				hlist_del(&nexthop_nh->nh_hash);
+			} endfor_nexthops(fi)
+		}
 		fi->fib_dead = 1;
 		fib_info_put(fi);
 	}
 	spin_unlock_bh(&fib_info_lock);
 }
 
-static inline int nh_comp(const struct fib_info *fi, const struct fib_info *ofi)
+static inline int nh_comp(struct fib_info *fi, struct fib_info *ofi)
 {
-	const struct fib_nh *onh = ofi->fib_nh;
+	const struct fib_nh *onh;
+
+	if (fi->nh || ofi->nh)
+		return nexthop_cmp(fi->nh, ofi->nh) ? 0 : -1;
+
+	if (ofi->fib_nhs == 0)
+		return 0;
 
 	for_nexthops(fi) {
+		onh = fib_info_nh(ofi, nhsel);
+
 		if (nh->fib_nh_oif != onh->fib_nh_oif ||
 		    nh->fib_nh_gw_family != onh->fib_nh_gw_family ||
 		    nh->fib_nh_scope != onh->fib_nh_scope ||
@@ -292,8 +312,6 @@ static inline int nh_comp(const struct fib_info *fi, const struct fib_info *ofi)
 		if (nh->fib_nh_gw_family == AF_INET6 &&
 		    ipv6_addr_cmp(&nh->fib_nh_gw6, &onh->fib_nh_gw6))
 			return -1;
-
-		onh++;
 	} endfor_nexthops(fi);
 	return 0;
 }
@@ -307,22 +325,78 @@ static inline unsigned int fib_devindex_hashfn(unsigned int val)
 		(val >> (DEVINDEX_HASHBITS * 2))) & mask;
 }
 
-static inline unsigned int fib_info_hashfn(const struct fib_info *fi)
+static unsigned int fib_info_hashfn_1(int init_val, u8 protocol, u8 scope,
+				      u32 prefsrc, u32 priority)
 {
-	unsigned int mask = (fib_info_hash_size - 1);
-	unsigned int val = fi->fib_nhs;
+	unsigned int val = init_val;
 
-	val ^= (fi->fib_protocol << 8) | fi->fib_scope;
-	val ^= (__force u32)fi->fib_prefsrc;
-	val ^= fi->fib_priority;
-	for_nexthops(fi) {
-		val ^= fib_devindex_hashfn(nh->fib_nh_oif);
-	} endfor_nexthops(fi)
+	val ^= (protocol << 8) | scope;
+	val ^= prefsrc;
+	val ^= priority;
+
+	return val;
+}
+
+static unsigned int fib_info_hashfn_result(unsigned int val)
+{
+	unsigned int mask = (fib_info_hash_size - 1);
 
 	return (val ^ (val >> 7) ^ (val >> 12)) & mask;
 }
 
-static struct fib_info *fib_find_info(const struct fib_info *nfi)
+static inline unsigned int fib_info_hashfn(struct fib_info *fi)
+{
+	unsigned int val;
+
+	val = fib_info_hashfn_1(fi->fib_nhs, fi->fib_protocol,
+				fi->fib_scope, (__force u32)fi->fib_prefsrc,
+				fi->fib_priority);
+
+	if (fi->nh) {
+		val ^= fib_devindex_hashfn(fi->nh->id);
+	} else {
+		for_nexthops(fi) {
+			val ^= fib_devindex_hashfn(nh->fib_nh_oif);
+		} endfor_nexthops(fi)
+	}
+
+	return fib_info_hashfn_result(val);
+}
+
+/* no metrics, only nexthop id */
+static struct fib_info *fib_find_info_nh(struct net *net,
+					 const struct fib_config *cfg)
+{
+	struct hlist_head *head;
+	struct fib_info *fi;
+	unsigned int hash;
+
+	hash = fib_info_hashfn_1(fib_devindex_hashfn(cfg->fc_nh_id),
+				 cfg->fc_protocol, cfg->fc_scope,
+				 (__force u32)cfg->fc_prefsrc,
+				 cfg->fc_priority);
+	hash = fib_info_hashfn_result(hash);
+	head = &fib_info_hash[hash];
+
+	hlist_for_each_entry(fi, head, fib_hash) {
+		if (!net_eq(fi->fib_net, net))
+			continue;
+		if (!fi->nh || fi->nh->id != cfg->fc_nh_id)
+			continue;
+		if (cfg->fc_protocol == fi->fib_protocol &&
+		    cfg->fc_scope == fi->fib_scope &&
+		    cfg->fc_prefsrc == fi->fib_prefsrc &&
+		    cfg->fc_priority == fi->fib_priority &&
+		    cfg->fc_type == fi->fib_type &&
+		    cfg->fc_table == fi->fib_tb_id &&
+		    !((cfg->fc_flags ^ fi->fib_flags) & ~RTNH_COMPARE_MASK))
+			return fi;
+	}
+
+	return NULL;
+}
+
+static struct fib_info *fib_find_info(struct fib_info *nfi)
 {
 	struct hlist_head *head;
 	struct fib_info *fi;
@@ -344,7 +418,7 @@ static struct fib_info *fib_find_info(const struct fib_info *nfi)
 		    memcmp(nfi->fib_metrics, fi->fib_metrics,
 			   sizeof(u32) * RTAX_MAX) == 0 &&
 		    !((nfi->fib_flags ^ fi->fib_flags) & ~RTNH_COMPARE_MASK) &&
-		    (nfi->fib_nhs == 0 || nh_comp(fi, nfi) == 0))
+		    nh_comp(fi, nfi) == 0)
 			return fi;
 	}
 
@@ -386,34 +460,40 @@ static inline size_t fib_nlmsg_size(struct fib_info *fi)
 			 + nla_total_size(4) /* RTA_PRIORITY */
 			 + nla_total_size(4) /* RTA_PREFSRC */
 			 + nla_total_size(TCP_CA_NAME_MAX); /* RTAX_CC_ALGO */
+	unsigned int nhs = fib_info_num_path(fi);
 
 	/* space for nested metrics */
 	payload += nla_total_size((RTAX_MAX * nla_total_size(4)));
 
-	if (fi->fib_nhs) {
+	if (fi->nh)
+		payload += nla_total_size(4); /* RTA_NH_ID */
+
+	if (nhs) {
 		size_t nh_encapsize = 0;
-		/* Also handles the special case fib_nhs == 1 */
+		/* Also handles the special case nhs == 1 */
 
 		/* each nexthop is packed in an attribute */
 		size_t nhsize = nla_total_size(sizeof(struct rtnexthop));
+		unsigned int i;
 
 		/* may contain flow and gateway attribute */
 		nhsize += 2 * nla_total_size(4);
 
 		/* grab encap info */
-		for_nexthops(fi) {
-			if (nh->fib_nh_lws) {
+		for (i = 0; i < fib_info_num_path(fi); i++) {
+			struct fib_nh_common *nhc = fib_info_nhc(fi, i);
+
+			if (nhc->nhc_lwtstate) {
 				/* RTA_ENCAP_TYPE */
 				nh_encapsize += lwtunnel_get_encap_size(
-						nh->fib_nh_lws);
+						nhc->nhc_lwtstate);
 				/* RTA_ENCAP */
 				nh_encapsize +=  nla_total_size(2);
 			}
-		} endfor_nexthops(fi);
+		}
 
 		/* all nexthops are packed in a nested attribute */
-		payload += nla_total_size((fi->fib_nhs * nhsize) +
-					  nh_encapsize);
+		payload += nla_total_size((nhs * nhsize) + nh_encapsize);
 
 	}
 
@@ -574,12 +654,14 @@ static int fib_count_nexthops(struct rtnexthop *rtnh, int remaining,
 	return nhs;
 }
 
+/* only called when fib_nh is integrated into fib_info */
 static int fib_get_nhs(struct fib_info *fi, struct rtnexthop *rtnh,
 		       int remaining, struct fib_config *cfg,
 		       struct netlink_ext_ack *extack)
 {
 	struct net *net = fi->fib_net;
 	struct fib_config fib_cfg;
+	struct fib_nh *nh;
 	int ret;
 
 	change_nexthops(fi) {
@@ -642,24 +724,25 @@ static int fib_get_nhs(struct fib_info *fi, struct rtnexthop *rtnh,
 	} endfor_nexthops(fi);
 
 	ret = -EINVAL;
-	if (cfg->fc_oif && fi->fib_nh->fib_nh_oif != cfg->fc_oif) {
+	nh = fib_info_nh(fi, 0);
+	if (cfg->fc_oif && nh->fib_nh_oif != cfg->fc_oif) {
 		NL_SET_ERR_MSG(extack,
 			       "Nexthop device index does not match RTA_OIF");
 		goto errout;
 	}
 	if (cfg->fc_gw_family) {
-		if (cfg->fc_gw_family != fi->fib_nh->fib_nh_gw_family ||
+		if (cfg->fc_gw_family != nh->fib_nh_gw_family ||
 		    (cfg->fc_gw_family == AF_INET &&
-		     fi->fib_nh->fib_nh_gw4 != cfg->fc_gw4) ||
+		     nh->fib_nh_gw4 != cfg->fc_gw4) ||
 		    (cfg->fc_gw_family == AF_INET6 &&
-		     ipv6_addr_cmp(&fi->fib_nh->fib_nh_gw6, &cfg->fc_gw6))) {
+		     ipv6_addr_cmp(&nh->fib_nh_gw6, &cfg->fc_gw6))) {
 			NL_SET_ERR_MSG(extack,
 				       "Nexthop gateway does not match RTA_GATEWAY or RTA_VIA");
 			goto errout;
 		}
 	}
 #ifdef CONFIG_IP_ROUTE_CLASSID
-	if (cfg->fc_flow && fi->fib_nh->nh_tclassid != cfg->fc_flow) {
+	if (cfg->fc_flow && nh->nh_tclassid != cfg->fc_flow) {
 		NL_SET_ERR_MSG(extack,
 			       "Nexthop class id does not match RTA_FLOW");
 		goto errout;
@@ -670,12 +753,13 @@ errout:
 	return ret;
 }
 
+/* only called when fib_nh is integrated into fib_info */
 static void fib_rebalance(struct fib_info *fi)
 {
 	int total;
 	int w;
 
-	if (fi->fib_nhs < 2)
+	if (fib_info_num_path(fi) < 2)
 		return;
 
 	total = 0;
@@ -756,28 +840,36 @@ int fib_nh_match(struct fib_config *cfg, struct fib_info *fi,
 	if (cfg->fc_priority && cfg->fc_priority != fi->fib_priority)
 		return 1;
 
+	if (cfg->fc_nh_id) {
+		if (fi->nh && cfg->fc_nh_id == fi->nh->id)
+			return 0;
+		return 1;
+	}
+
 	if (cfg->fc_oif || cfg->fc_gw_family) {
+		struct fib_nh *nh = fib_info_nh(fi, 0);
+
 		if (cfg->fc_encap) {
 			if (fib_encap_match(cfg->fc_encap_type, cfg->fc_encap,
-					    fi->fib_nh, cfg, extack))
+					    nh, cfg, extack))
 				return 1;
 		}
 #ifdef CONFIG_IP_ROUTE_CLASSID
 		if (cfg->fc_flow &&
-		    cfg->fc_flow != fi->fib_nh->nh_tclassid)
+		    cfg->fc_flow != nh->nh_tclassid)
 			return 1;
 #endif
-		if ((cfg->fc_oif && cfg->fc_oif != fi->fib_nh->fib_nh_oif) ||
+		if ((cfg->fc_oif && cfg->fc_oif != nh->fib_nh_oif) ||
 		    (cfg->fc_gw_family &&
-		     cfg->fc_gw_family != fi->fib_nh->fib_nh_gw_family))
+		     cfg->fc_gw_family != nh->fib_nh_gw_family))
 			return 1;
 
 		if (cfg->fc_gw_family == AF_INET &&
-		    cfg->fc_gw4 != fi->fib_nh->fib_nh_gw4)
+		    cfg->fc_gw4 != nh->fib_nh_gw4)
 			return 1;
 
 		if (cfg->fc_gw_family == AF_INET6 &&
-		    ipv6_addr_cmp(&cfg->fc_gw6, &fi->fib_nh->fib_nh_gw6))
+		    ipv6_addr_cmp(&cfg->fc_gw6, &nh->fib_nh_gw6))
 			return 1;
 
 		return 0;
@@ -1088,15 +1180,13 @@ out:
 	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
@@ -1187,11 +1277,16 @@ 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_nhc_saddr(struct net *net, struct fib_nh_common *nhc,
+				 unsigned char scope)
 {
-	nh->nh_saddr = inet_select_addr(nh->fib_nh_dev,
-					nh->fib_nh_gw4,
-					nh->nh_parent->fib_scope);
+	struct fib_nh *nh;
+
+	if (nhc->nhc_family != AF_INET)
+		return inet_select_addr(nhc->nhc_dev, 0, scope);
+
+	nh = container_of(nhc, struct fib_nh, nh_common);
+	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;
@@ -1200,16 +1295,19 @@ __be32 fib_info_update_nh_saddr(struct net *net, struct fib_nh *nh)
 __be32 fib_result_prefsrc(struct net *net, struct fib_result *res)
 {
 	struct fib_nh_common *nhc = res->nhc;
-	struct fib_nh *nh;
 
 	if (res->fi->fib_prefsrc)
 		return res->fi->fib_prefsrc;
 
-	nh = container_of(nhc, struct fib_nh, nh_common);
-	if (nh->nh_saddr_genid == atomic_read(&net->ipv4.dev_addr_genid))
-		return nh->nh_saddr;
+	if (nhc->nhc_family == AF_INET) {
+		struct fib_nh *nh;
+
+		nh = container_of(nhc, struct fib_nh, nh_common);
+		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_nhc_saddr(net, nhc, res->fi->fib_scope);
 }
 
 static bool fib_valid_prefsrc(struct fib_config *cfg, __be32 fib_prefsrc)
@@ -1241,6 +1339,7 @@ struct fib_info *fib_create_info(struct fib_config *cfg,
 {
 	int err;
 	struct fib_info *fi = NULL;
+	struct nexthop *nh = NULL;
 	struct fib_info *ofi;
 	int nhs = 1;
 	struct net *net = cfg->fc_nlinfo.nl_net;
@@ -1260,6 +1359,23 @@ struct fib_info *fib_create_info(struct fib_config *cfg,
 		goto err_inval;
 	}
 
+	if (cfg->fc_nh_id) {
+		if (!cfg->fc_mx) {
+			fi = fib_find_info_nh(net, cfg);
+			if (fi) {
+				fi->fib_treeref++;
+				return fi;
+			}
+		}
+
+		nh = nexthop_find_by_id(net, cfg->fc_nh_id);
+		if (!nh) {
+			NL_SET_ERR_MSG(extack, "Nexthop id does not exist");
+			goto err_inval;
+		}
+		nhs = 0;
+	}
+
 #ifdef CONFIG_IP_ROUTE_MULTIPATH
 	if (cfg->fc_mp) {
 		nhs = fib_count_nexthops(cfg->fc_mp, cfg->fc_mp_len, extack);
@@ -1295,7 +1411,7 @@ struct fib_info *fib_create_info(struct fib_config *cfg,
 		goto failure;
 	fi->fib_metrics = ip_fib_metrics_init(fi->fib_net, cfg->fc_mx,
 					      cfg->fc_mx_len, extack);
-	if (unlikely(IS_ERR(fi->fib_metrics))) {
+	if (IS_ERR(fi->fib_metrics)) {
 		err = PTR_ERR(fi->fib_metrics);
 		kfree(fi);
 		return ERR_PTR(err);
@@ -1312,14 +1428,25 @@ struct fib_info *fib_create_info(struct fib_config *cfg,
 	fi->fib_tb_id = cfg->fc_table;
 
 	fi->fib_nhs = nhs;
-	change_nexthops(fi) {
-		nexthop_nh->nh_parent = fi;
-	} endfor_nexthops(fi)
+	if (nh) {
+		if (!nexthop_get(nh)) {
+			NL_SET_ERR_MSG(extack, "Nexthop has been deleted");
+			err = -EINVAL;
+		} else {
+			err = 0;
+			fi->nh = nh;
+		}
+	} else {
+		change_nexthops(fi) {
+			nexthop_nh->nh_parent = fi;
+		} endfor_nexthops(fi)
 
-	if (cfg->fc_mp)
-		err = fib_get_nhs(fi, cfg->fc_mp, cfg->fc_mp_len, cfg, extack);
-	else
-		err = fib_nh_init(net, fi->fib_nh, cfg, 1, extack);
+		if (cfg->fc_mp)
+			err = fib_get_nhs(fi, cfg->fc_mp, cfg->fc_mp_len, cfg,
+					  extack);
+		else
+			err = fib_nh_init(net, fi->fib_nh, cfg, 1, extack);
+	}
 
 	if (err != 0)
 		goto failure;
@@ -1350,7 +1477,11 @@ struct fib_info *fib_create_info(struct fib_config *cfg,
 		goto err_inval;
 	}
 
-	if (cfg->fc_scope == RT_SCOPE_HOST) {
+	if (fi->nh) {
+		err = fib_check_nexthop(fi->nh, cfg->fc_scope, extack);
+		if (err)
+			goto failure;
+	} else if (cfg->fc_scope == RT_SCOPE_HOST) {
 		struct fib_nh *nh = fi->fib_nh;
 
 		/* Local address is added. */
@@ -1365,7 +1496,7 @@ struct fib_info *fib_create_info(struct fib_config *cfg,
 			goto err_inval;
 		}
 		nh->fib_nh_scope = RT_SCOPE_NOWHERE;
-		nh->fib_nh_dev = dev_get_by_index(net, fi->fib_nh->fib_nh_oif);
+		nh->fib_nh_dev = dev_get_by_index(net, nh->fib_nh_oif);
 		err = -ENODEV;
 		if (!nh->fib_nh_dev)
 			goto failure;
@@ -1373,7 +1504,9 @@ 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)
@@ -1388,13 +1521,16 @@ struct fib_info *fib_create_info(struct fib_config *cfg,
 		goto err_inval;
 	}
 
-	change_nexthops(fi) {
-		fib_info_update_nh_saddr(net, nexthop_nh);
-		if (nexthop_nh->fib_nh_gw_family == AF_INET6)
-			fi->fib_nh_is_v6 = true;
-	} endfor_nexthops(fi)
+	if (!fi->nh) {
+		change_nexthops(fi) {
+			fib_info_update_nhc_saddr(net, &nexthop_nh->nh_common,
+						  fi->fib_scope);
+			if (nexthop_nh->fib_nh_gw_family == AF_INET6)
+				fi->fib_nh_is_v6 = true;
+		} endfor_nexthops(fi)
 
-	fib_rebalance(fi);
+		fib_rebalance(fi);
+	}
 
 link_it:
 	ofi = fib_find_info(fi);
@@ -1416,16 +1552,20 @@ link_it:
 		head = &fib_info_laddrhash[fib_laddr_hashfn(fi->fib_prefsrc)];
 		hlist_add_head(&fi->fib_lhash, head);
 	}
-	change_nexthops(fi) {
-		struct hlist_head *head;
-		unsigned int hash;
+	if (fi->nh) {
+		list_add(&fi->nh_list, &nh->fi_list);
+	} else {
+		change_nexthops(fi) {
+			struct hlist_head *head;
+			unsigned int hash;
 
-		if (!nexthop_nh->fib_nh_dev)
-			continue;
-		hash = fib_devindex_hashfn(nexthop_nh->fib_nh_dev->ifindex);
-		head = &fib_info_devhash[hash];
-		hlist_add_head(&nexthop_nh->nh_hash, head);
-	} endfor_nexthops(fi)
+			if (!nexthop_nh->fib_nh_dev)
+				continue;
+			hash = fib_devindex_hashfn(nexthop_nh->fib_nh_dev->ifindex);
+			head = &fib_info_devhash[hash];
+			hlist_add_head(&nexthop_nh->nh_hash, head);
+		} endfor_nexthops(fi)
+	}
 	spin_unlock_bh(&fib_info_lock);
 	return fi;
 
@@ -1552,6 +1692,12 @@ static int fib_add_multipath(struct sk_buff *skb, struct fib_info *fi)
 	if (!mp)
 		goto nla_put_failure;
 
+	if (unlikely(fi->nh)) {
+		if (nexthop_mpath_fill_node(skb, fi->nh) < 0)
+			goto nla_put_failure;
+		goto mp_end;
+	}
+
 	for_nexthops(fi) {
 		if (fib_add_nexthop(skb, &nh->nh_common, nh->fib_nh_weight) < 0)
 			goto nla_put_failure;
@@ -1562,6 +1708,7 @@ static int fib_add_multipath(struct sk_buff *skb, struct fib_info *fi)
 #endif
 	} endfor_nexthops(fi);
 
+mp_end:
 	nla_nest_end(skb, mp);
 
 	return 0;
@@ -1580,6 +1727,7 @@ int fib_dump_info(struct sk_buff *skb, u32 portid, u32 seq, int event,
 		  u32 tb_id, u8 type, __be32 dst, int dst_len, u8 tos,
 		  struct fib_info *fi, unsigned int flags)
 {
+	unsigned int nhs = fib_info_num_path(fi);
 	struct nlmsghdr *nlh;
 	struct rtmsg *rtm;
 
@@ -1615,18 +1763,31 @@ int fib_dump_info(struct sk_buff *skb, u32 portid, u32 seq, int event,
 	if (fi->fib_prefsrc &&
 	    nla_put_in_addr(skb, RTA_PREFSRC, fi->fib_prefsrc))
 		goto nla_put_failure;
-	if (fi->fib_nhs == 1) {
-		struct fib_nh *nh = &fi->fib_nh[0];
+
+	if (fi->nh) {
+		if (nla_put_u32(skb, RTA_NH_ID, fi->nh->id))
+			goto nla_put_failure;
+		if (nexthop_is_blackhole(fi->nh))
+			rtm->rtm_type = RTN_BLACKHOLE;
+	}
+
+	if (nhs == 1) {
+		const struct fib_nh_common *nhc = fib_info_nhc(fi, 0);
 		unsigned char flags = 0;
 
-		if (fib_nexthop_info(skb, &nh->nh_common, &flags, false) < 0)
+		if (fib_nexthop_info(skb, nhc, &flags, false) < 0)
 			goto nla_put_failure;
 
 		rtm->rtm_flags = flags;
 #ifdef CONFIG_IP_ROUTE_CLASSID
-		if (nh->nh_tclassid &&
-		    nla_put_u32(skb, RTA_FLOW, nh->nh_tclassid))
-			goto nla_put_failure;
+		if (nhc->nhc_family == AF_INET) {
+			struct fib_nh *nh;
+
+			nh = container_of(nhc, struct fib_nh, nh_common);
+			if (nh->nh_tclassid &&
+			    nla_put_u32(skb, RTA_FLOW, nh->nh_tclassid))
+				goto nla_put_failure;
+		}
 #endif
 	} else {
 		if (fib_add_multipath(skb, fi) < 0)
@@ -1709,7 +1870,7 @@ 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;
@@ -1745,7 +1906,7 @@ 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);
 	}
 }
 
@@ -1754,6 +1915,8 @@ void fib_sync_mtu(struct net_device *dev, u32 orig_mtu)
  * NETDEV_DOWN        0     LINKDOWN|DEAD   Link down, not for scope host
  * NETDEV_DOWN        1     LINKDOWN|DEAD   Last address removed
  * NETDEV_UNREGISTER  1     LINKDOWN|DEAD   Device removed
+ *
+ * only used when fib_nh is built into fib_info
  */
 int fib_sync_down_dev(struct net_device *dev, unsigned long event, bool force)
 {
@@ -1835,6 +1998,7 @@ static void fib_select_default(const struct flowi4 *flp, struct fib_result *res)
 
 	hlist_for_each_entry_rcu(fa, fa_head, fa_list) {
 		struct fib_info *next_fi = fa->fa_info;
+		struct fib_nh *nh;
 
 		if (fa->fa_slen != slen)
 			continue;
@@ -1856,8 +2020,9 @@ static void fib_select_default(const struct flowi4 *flp, struct fib_result *res)
 		if (next_fi->fib_scope != res->scope ||
 		    fa->fa_type != RTN_UNICAST)
 			continue;
-		if (!next_fi->fib_nh[0].fib_nh_gw4 ||
-		    next_fi->fib_nh[0].fib_nh_scope != RT_SCOPE_LINK)
+
+		nh = fib_info_nh(next_fi, 0);
+		if (!nh->fib_nh_gw4 || nh->fib_nh_scope != RT_SCOPE_LINK)
 			continue;
 
 		fib_alias_accessed(fa);
@@ -1899,6 +2064,8 @@ out:
 /*
  * Dead device goes up. We wake up dead nexthops.
  * It takes sense only on multipath routes.
+ *
+ * only used when fib_nh is built into fib_info
  */
 int fib_sync_up(struct net_device *dev, unsigned char nh_flags)
 {
@@ -1993,6 +2160,11 @@ void fib_select_multipath(struct fib_result *res, int hash)
 	struct net *net = fi->fib_net;
 	bool first = false;
 
+	if (unlikely(res->fi->nh)) {
+		nexthop_path_fib_result(res, hash);
+		return;
+	}
+
 	change_nexthops(fi) {
 		if (net->ipv4.sysctl_fib_multipath_use_neigh) {
 			if (!fib_good_nh(nexthop_nh))
@@ -2021,7 +2193,7 @@ void fib_select_path(struct net *net, struct fib_result *res,
 		goto check_saddr;
 
 #ifdef CONFIG_IP_ROUTE_MULTIPATH
-	if (res->fi->fib_nhs > 1) {
+	if (fib_info_num_path(res->fi) > 1) {
 		int h = fib_multipath_hash(net, fl4, skb, NULL);
 
 		fib_select_multipath(res, h);