[PATCH v4 net-next 0/5] net: More movement to fib_nh_common

[PATCH v4 net-next 0/5] net: More movement to fib_nh_common

[David Ahern]

From: David Ahern <dsahern@gmail.com>

Second set of three with the end goal of enabling IPv6 gateways with IPv4
routes.

This set moves:
- the ipv4 tracepoint to take a fib_nh_common and updates it to handle
  a v6 gateway.
- consolidates route notifications to use the same fill functions
  for both ipv4 and ipv6

v4
- enhanced the commit message for patches 1 and 2

v3
- comments from Martin:
  + renamed FIB_RES_NH to FIB_RES_NHC
  + removed family check from fib_result_prefsrc
  + in fib_nexthop_info, renamed nexthop arg to nhc and dropped for_ipv4 arg

v2
- dropped patches moving cached routes and exception buckets to
  fib_nh_common. The goal is allowing a fib6_nh to be used with an
  IPv4 route. The hold up is the need for separate exception buckets -
  one for v6 routes and one for v4 routes. When all of the nexthop patches
  are in, adding a secondi exception bucket pushes IPv6 fib6_info
  allocations over 256 which means fib6_info allocations roll up to 512.
  Hence, deferring the patches until some data mining can be done to keep
  the allocations at 256.

David Ahern (5):
  ipv4: Update fib_table_lookup tracepoint to take common nexthop
  ipv4: Add fib_nh_common to fib_result
  ipv4: Refactor nexthop attributes in fib_dump_info
  ipv4: Change fib_nexthop_info and fib_add_nexthop to take
    fib_nh_common
  ipv6: Flip to fib_nexthop_info

 include/net/ip_fib.h       |  52 +++++------
 include/trace/events/fib.h |  45 ++++++----
 net/core/filter.c          |  12 +--
 net/ipv4/fib_frontend.c    |   6 +-
 net/ipv4/fib_lookup.h      |   1 +
 net/ipv4/fib_semantics.c   | 215 ++++++++++++++++++++++++++++++++-------------
 net/ipv4/fib_trie.c        |  13 +--
 net/ipv4/route.c           |  60 ++++++++-----
 net/ipv6/route.c           |  77 ++--------------
 9 files changed, 267 insertions(+), 214 deletions(-)

-- 
2.11.0

[PATCH v4 net-next 1/5] ipv4: Update fib_table_lookup tracepoint to take common nexthop

[David Ahern]

From: David Ahern <dsahern@gmail.com>

Update fib_table_lookup tracepoint to take a fib_nh_common struct and
dump the v6 gateway address if the nexthop uses it.

Over the years saddr has not proven useful and the output of the
tracepoint produces very long lines. Since saddr is not part of
fib_nh_common, drop it. If it needs to be added later, fib_nh which
contains saddr can be obtained from a fib_nh_common via container_of.

Signed-off-by: David Ahern <dsahern@gmail.com>
---
 include/trace/events/fib.h | 45 ++++++++++++++++++++++++++-------------------
 net/ipv4/fib_trie.c        |  2 +-
 2 files changed, 27 insertions(+), 20 deletions(-)

diff --git a/include/trace/events/fib.h b/include/trace/events/fib.h
index 61ea7a24c8e5..7f83b6eafc5c 100644
--- a/include/trace/events/fib.h
+++ b/include/trace/events/fib.h
@@ -13,9 +13,9 @@
 TRACE_EVENT(fib_table_lookup,
 
 	TP_PROTO(u32 tb_id, const struct flowi4 *flp,
-		 const struct fib_nh *nh, int err),
+		 const struct fib_nh_common *nhc, int err),
 
-	TP_ARGS(tb_id, flp, nh, err),
+	TP_ARGS(tb_id, flp, nhc, err),
 
 	TP_STRUCT__entry(
 		__field(	u32,	tb_id		)
@@ -28,14 +28,17 @@ TRACE_EVENT(fib_table_lookup,
 		__field(	__u8,	flags		)
 		__array(	__u8,	src,	4	)
 		__array(	__u8,	dst,	4	)
-		__array(	__u8,	gw,	4	)
-		__array(	__u8,	saddr,	4	)
+		__array(	__u8,	gw4,	4	)
+		__array(	__u8,	gw6,	16	)
 		__field(	u16,	sport		)
 		__field(	u16,	dport		)
 		__dynamic_array(char,  name,   IFNAMSIZ )
 	),
 
 	TP_fast_assign(
+		struct in6_addr in6_zero = {};
+		struct net_device *dev;
+		struct in6_addr *in6;
 		__be32 *p32;
 
 		__entry->tb_id = tb_id;
@@ -62,33 +65,37 @@ TRACE_EVENT(fib_table_lookup,
 			__entry->dport = 0;
 		}
 
-		if (nh) {
-			struct net_device *dev;
+		dev = nhc ? nhc->nhc_dev : NULL;
+		__assign_str(name, dev ? dev->name : "-");
 
-			p32 = (__be32 *) __entry->saddr;
-			*p32 = nh->nh_saddr;
+		if (nhc) {
+			if (nhc->nhc_family == AF_INET) {
+				p32 = (__be32 *) __entry->gw4;
+				*p32 = nhc->nhc_gw.ipv4;
 
-			p32 = (__be32 *) __entry->gw;
-			*p32 = nh->fib_nh_gw4;
+				in6 = (struct in6_addr *)__entry->gw6;
+				*in6 = in6_zero;
+			} else if (nhc->nhc_family == AF_INET6) {
+				p32 = (__be32 *) __entry->gw4;
+				*p32 = 0;
 
-			dev = nh->fib_nh_dev;
-			__assign_str(name, dev ? dev->name : "-");
+				in6 = (struct in6_addr *)__entry->gw6;
+				*in6 = nhc->nhc_gw.ipv6;
+			}
 		} else {
-			p32 = (__be32 *) __entry->saddr;
+			p32 = (__be32 *) __entry->gw4;
 			*p32 = 0;
 
-			p32 = (__be32 *) __entry->gw;
-			*p32 = 0;
-
-			__assign_str(name, "-");
+			in6 = (struct in6_addr *)__entry->gw6;
+			*in6 = in6_zero;
 		}
 	),
 
-	TP_printk("table %u oif %d iif %d proto %u %pI4/%u -> %pI4/%u tos %d scope %d flags %x ==> dev %s gw %pI4 src %pI4 err %d",
+	TP_printk("table %u oif %d iif %d proto %u %pI4/%u -> %pI4/%u tos %d scope %d flags %x ==> dev %s gw %pI4/%pI6c err %d",
 		  __entry->tb_id, __entry->oif, __entry->iif, __entry->proto,
 		  __entry->src, __entry->sport, __entry->dst, __entry->dport,
 		  __entry->tos, __entry->scope, __entry->flags,
-		  __get_str(name), __entry->gw, __entry->saddr, __entry->err)
+		  __get_str(name), __entry->gw4, __entry->gw6, __entry->err)
 );
 #endif /* _TRACE_FIB_H */
 
diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c
index 1e3b492690f9..13b3327206f9 100644
--- a/net/ipv4/fib_trie.c
+++ b/net/ipv4/fib_trie.c
@@ -1498,7 +1498,7 @@ int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp,
 #ifdef CONFIG_IP_FIB_TRIE_STATS
 			this_cpu_inc(stats->semantic_match_passed);
 #endif
-			trace_fib_table_lookup(tb->tb_id, flp, nh, err);
+			trace_fib_table_lookup(tb->tb_id, flp, &nh->nh_common, err);
 
 			return err;
 		}
-- 
2.11.0

[PATCH v4 net-next 2/5] ipv4: Add fib_nh_common to fib_result

[David Ahern]

From: David Ahern <dsahern@gmail.com>

Most of the ipv4 code only needs data from fib_nh_common. Add
fib_nh_common selection to fib_result and update users to use it.

Right now, fib_nh_common in fib_result will point to a fib_nh struct
that is embedded within a fib_info:

        fib_info  --> fib_nh
                      fib_nh
                      ...
                      fib_nh
                        ^
    fib_result->nhc ----+

Later, nhc can point to a fib_nh within a nexthop struct:

        fib_info --> nexthop --> fib_nh
                                   ^
    fib_result->nhc ---------------+

or for a nexthop group:

        fib_info --> nexthop --> nexthop --> fib_nh
                                 nexthop --> fib_nh
                                 ...
                                 nexthop --> fib_nh
                                               ^
    fib_result->nhc ---------------------------+

In all cases nhsel within fib_result will point to which leg in the
multipath route is used.

Signed-off-by: David Ahern <dsahern@gmail.com>
---
 include/net/ip_fib.h     | 47 +++++++++++++++++--------------------
 net/core/filter.c        | 12 +++++-----
 net/ipv4/fib_frontend.c  |  6 ++---
 net/ipv4/fib_lookup.h    |  1 +
 net/ipv4/fib_semantics.c | 25 ++++++++++++++++----
 net/ipv4/fib_trie.c      | 13 ++++++-----
 net/ipv4/route.c         | 60 ++++++++++++++++++++++++++++++++----------------
 7 files changed, 99 insertions(+), 65 deletions(-)

diff --git a/include/net/ip_fib.h b/include/net/ip_fib.h
index 12a6d759cf57..1f4a3b8bf584 100644
--- a/include/net/ip_fib.h
+++ b/include/net/ip_fib.h
@@ -156,15 +156,16 @@ struct fib_rule;
 
 struct fib_table;
 struct fib_result {
-	__be32		prefix;
-	unsigned char	prefixlen;
-	unsigned char	nh_sel;
-	unsigned char	type;
-	unsigned char	scope;
-	u32		tclassid;
-	struct fib_info *fi;
-	struct fib_table *table;
-	struct hlist_head *fa_head;
+	__be32			prefix;
+	unsigned char		prefixlen;
+	unsigned char		nh_sel;
+	unsigned char		type;
+	unsigned char		scope;
+	u32			tclassid;
+	struct fib_nh_common	*nhc;
+	struct fib_info		*fi;
+	struct fib_table	*table;
+	struct hlist_head	*fa_head;
 };
 
 struct fib_result_nl {
@@ -182,11 +183,10 @@ struct fib_result_nl {
 	int             err;
 };
 
-#ifdef CONFIG_IP_ROUTE_MULTIPATH
-#define FIB_RES_NH(res)		((res).fi->fib_nh[(res).nh_sel])
-#else /* CONFIG_IP_ROUTE_MULTIPATH */
-#define FIB_RES_NH(res)		((res).fi->fib_nh[0])
-#endif /* CONFIG_IP_ROUTE_MULTIPATH */
+static inline struct fib_nh_common *fib_info_nhc(struct fib_info *fi, int nhsel)
+{
+	return &fi->fib_nh[nhsel].nh_common;
+}
 
 #ifdef CONFIG_IP_MULTIPLE_TABLES
 #define FIB_TABLE_HASHSZ 256
@@ -195,18 +195,11 @@ struct fib_result_nl {
 #endif
 
 __be32 fib_info_update_nh_saddr(struct net *net, struct fib_nh *nh);
+__be32 fib_result_prefsrc(struct net *net, struct fib_result *res);
 
-#define FIB_RES_SADDR(net, res)				\
-	((FIB_RES_NH(res).nh_saddr_genid ==		\
-	  atomic_read(&(net)->ipv4.dev_addr_genid)) ?	\
-	 FIB_RES_NH(res).nh_saddr :			\
-	 fib_info_update_nh_saddr((net), &FIB_RES_NH(res)))
-#define FIB_RES_GW(res)			(FIB_RES_NH(res).fib_nh_gw4)
-#define FIB_RES_DEV(res)		(FIB_RES_NH(res).fib_nh_dev)
-#define FIB_RES_OIF(res)		(FIB_RES_NH(res).fib_nh_oif)
-
-#define FIB_RES_PREFSRC(net, res)	((res).fi->fib_prefsrc ? : \
-					 FIB_RES_SADDR(net, res))
+#define FIB_RES_NHC(res)		((res).nhc)
+#define FIB_RES_DEV(res)	(FIB_RES_NHC(res)->nhc_dev)
+#define FIB_RES_OIF(res)	(FIB_RES_NHC(res)->nhc_oif)
 
 struct fib_entry_notifier_info {
 	struct fib_notifier_info info; /* must be first */
@@ -453,10 +446,12 @@ struct fib_table *fib_trie_table(u32 id, struct fib_table *alias);
 static inline void fib_combine_itag(u32 *itag, const struct fib_result *res)
 {
 #ifdef CONFIG_IP_ROUTE_CLASSID
+	struct fib_nh_common *nhc = res->nhc;
+	struct fib_nh *nh = container_of(nhc, struct fib_nh, nh_common);
 #ifdef CONFIG_IP_MULTIPLE_TABLES
 	u32 rtag;
 #endif
-	*itag = FIB_RES_NH(*res).nh_tclassid<<16;
+	*itag = nh->nh_tclassid << 16;
 #ifdef CONFIG_IP_MULTIPLE_TABLES
 	rtag = res->tclassid;
 	if (*itag == 0)
diff --git a/net/core/filter.c b/net/core/filter.c
index cdaafa3322db..08b53af84132 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -4555,11 +4555,11 @@ static int bpf_fib_set_fwd_params(struct bpf_fib_lookup *params,
 static int bpf_ipv4_fib_lookup(struct net *net, struct bpf_fib_lookup *params,
 			       u32 flags, bool check_mtu)
 {
+	struct fib_nh_common *nhc;
 	struct in_device *in_dev;
 	struct neighbour *neigh;
 	struct net_device *dev;
 	struct fib_result res;
-	struct fib_nh *nh;
 	struct flowi4 fl4;
 	int err;
 	u32 mtu;
@@ -4632,15 +4632,15 @@ static int bpf_ipv4_fib_lookup(struct net *net, struct bpf_fib_lookup *params,
 			return BPF_FIB_LKUP_RET_FRAG_NEEDED;
 	}
 
-	nh = &res.fi->fib_nh[res.nh_sel];
+	nhc = res.nhc;
 
 	/* do not handle lwt encaps right now */
-	if (nh->fib_nh_lws)
+	if (nhc->nhc_lwtstate)
 		return BPF_FIB_LKUP_RET_UNSUPP_LWT;
 
-	dev = nh->fib_nh_dev;
-	if (nh->fib_nh_gw4)
-		params->ipv4_dst = nh->fib_nh_gw4;
+	dev = nhc->nhc_dev;
+	if (nhc->nhc_has_gw)
+		params->ipv4_dst = nhc->nhc_gw.ipv4;
 
 	params->rt_metric = res.fi->fib_priority;
 
diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c
index ffbe24397dbe..15f779bd26b3 100644
--- a/net/ipv4/fib_frontend.c
+++ b/net/ipv4/fib_frontend.c
@@ -307,7 +307,7 @@ __be32 fib_compute_spec_dst(struct sk_buff *skb)
 			.flowi4_mark = vmark ? skb->mark : 0,
 		};
 		if (!fib_lookup(net, &fl4, &res, 0))
-			return FIB_RES_PREFSRC(net, res);
+			return fib_result_prefsrc(net, &res);
 	} else {
 		scope = RT_SCOPE_LINK;
 	}
@@ -390,7 +390,7 @@ static int __fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
 
 	dev_match = fib_info_nh_uses_dev(res.fi, dev);
 	if (dev_match) {
-		ret = FIB_RES_NH(res).fib_nh_scope >= RT_SCOPE_HOST;
+		ret = FIB_RES_NHC(res)->nhc_scope >= RT_SCOPE_HOST;
 		return ret;
 	}
 	if (no_addr)
@@ -402,7 +402,7 @@ static int __fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
 	ret = 0;
 	if (fib_lookup(net, &fl4, &res, FIB_LOOKUP_IGNORE_LINKSTATE) == 0) {
 		if (res.type == RTN_UNICAST)
-			ret = FIB_RES_NH(res).fib_nh_scope >= RT_SCOPE_HOST;
+			ret = FIB_RES_NHC(res)->nhc_scope >= RT_SCOPE_HOST;
 	}
 	return ret;
 
diff --git a/net/ipv4/fib_lookup.h b/net/ipv4/fib_lookup.h
index e6ff282bb7f4..7945f0534db7 100644
--- a/net/ipv4/fib_lookup.h
+++ b/net/ipv4/fib_lookup.h
@@ -45,6 +45,7 @@ static inline void fib_result_assign(struct fib_result *res,
 {
 	/* we used to play games with refcounts, but we now use RCU */
 	res->fi = fi;
+	res->nhc = fib_info_nhc(fi, 0);
 }
 
 struct fib_prop {
diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c
index df777af7e278..42666a409da0 100644
--- a/net/ipv4/fib_semantics.c
+++ b/net/ipv4/fib_semantics.c
@@ -1075,6 +1075,21 @@ __be32 fib_info_update_nh_saddr(struct net *net, struct fib_nh *nh)
 	return nh->nh_saddr;
 }
 
+__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;
+
+	return fib_info_update_nh_saddr(net, nh);
+}
+
 static bool fib_valid_prefsrc(struct fib_config *cfg, __be32 fib_prefsrc)
 {
 	if (cfg->fc_type != RTN_LOCAL || !cfg->fc_dst ||
@@ -1762,20 +1777,22 @@ void fib_select_multipath(struct fib_result *res, int hash)
 	struct net *net = fi->fib_net;
 	bool first = false;
 
-	for_nexthops(fi) {
+	change_nexthops(fi) {
 		if (net->ipv4.sysctl_fib_multipath_use_neigh) {
-			if (!fib_good_nh(nh))
+			if (!fib_good_nh(nexthop_nh))
 				continue;
 			if (!first) {
 				res->nh_sel = nhsel;
+				res->nhc = &nexthop_nh->nh_common;
 				first = true;
 			}
 		}
 
-		if (hash > atomic_read(&nh->fib_nh_upper_bound))
+		if (hash > atomic_read(&nexthop_nh->fib_nh_upper_bound))
 			continue;
 
 		res->nh_sel = nhsel;
+		res->nhc = &nexthop_nh->nh_common;
 		return;
 	} endfor_nexthops(fi);
 }
@@ -1802,5 +1819,5 @@ void fib_select_path(struct net *net, struct fib_result *res,
 
 check_saddr:
 	if (!fl4->saddr)
-		fl4->saddr = FIB_RES_PREFSRC(net, *res);
+		fl4->saddr = fib_result_prefsrc(net, res);
 }
diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c
index 13b3327206f9..334f723bdf80 100644
--- a/net/ipv4/fib_trie.c
+++ b/net/ipv4/fib_trie.c
@@ -1470,17 +1470,17 @@ int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp,
 		if (fi->fib_flags & RTNH_F_DEAD)
 			continue;
 		for (nhsel = 0; nhsel < fi->fib_nhs; nhsel++) {
-			const struct fib_nh *nh = &fi->fib_nh[nhsel];
+			struct fib_nh_common *nhc = fib_info_nhc(fi, nhsel);
 
-			if (nh->fib_nh_flags & RTNH_F_DEAD)
+			if (nhc->nhc_flags & RTNH_F_DEAD)
 				continue;
-			if (ip_ignore_linkdown(nh->fib_nh_dev) &&
-			    nh->fib_nh_flags & RTNH_F_LINKDOWN &&
+			if (ip_ignore_linkdown(nhc->nhc_dev) &&
+			    nhc->nhc_flags & RTNH_F_LINKDOWN &&
 			    !(fib_flags & FIB_LOOKUP_IGNORE_LINKSTATE))
 				continue;
 			if (!(flp->flowi4_flags & FLOWI_FLAG_SKIP_NH_OIF)) {
 				if (flp->flowi4_oif &&
-				    flp->flowi4_oif != nh->fib_nh_oif)
+				    flp->flowi4_oif != nhc->nhc_oif)
 					continue;
 			}
 
@@ -1490,6 +1490,7 @@ int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp,
 			res->prefix = htonl(n->key);
 			res->prefixlen = KEYLENGTH - fa->fa_slen;
 			res->nh_sel = nhsel;
+			res->nhc = nhc;
 			res->type = fa->fa_type;
 			res->scope = fi->fib_scope;
 			res->fi = fi;
@@ -1498,7 +1499,7 @@ int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp,
 #ifdef CONFIG_IP_FIB_TRIE_STATS
 			this_cpu_inc(stats->semantic_match_passed);
 #endif
-			trace_fib_table_lookup(tb->tb_id, flp, &nh->nh_common, err);
+			trace_fib_table_lookup(tb->tb_id, flp, nhc, err);
 
 			return err;
 		}
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 7977514d90f5..f3f2adf630d4 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -778,8 +778,10 @@ static void __ip_do_redirect(struct rtable *rt, struct sk_buff *skb, struct flow
 			neigh_event_send(n, NULL);
 		} else {
 			if (fib_lookup(net, fl4, &res, 0) == 0) {
-				struct fib_nh *nh = &FIB_RES_NH(res);
+				struct fib_nh_common *nhc = FIB_RES_NHC(res);
+				struct fib_nh *nh;
 
+				nh = container_of(nhc, struct fib_nh, nh_common);
 				update_or_create_fnhe(nh, fl4->daddr, new_gw,
 						0, false,
 						jiffies + ip_rt_gc_timeout);
@@ -1027,8 +1029,10 @@ static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu)
 
 	rcu_read_lock();
 	if (fib_lookup(dev_net(dst->dev), fl4, &res, 0) == 0) {
-		struct fib_nh *nh = &FIB_RES_NH(res);
+		struct fib_nh_common *nhc = FIB_RES_NHC(res);
+		struct fib_nh *nh;
 
+		nh = container_of(nhc, struct fib_nh, nh_common);
 		update_or_create_fnhe(nh, fl4->daddr, 0, mtu, lock,
 				      jiffies + ip_rt_mtu_expires);
 	}
@@ -1235,7 +1239,7 @@ void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt)
 
 		rcu_read_lock();
 		if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res, 0) == 0)
-			src = FIB_RES_PREFSRC(dev_net(rt->dst.dev), res);
+			src = fib_result_prefsrc(dev_net(rt->dst.dev), &res);
 		else
 			src = inet_select_addr(rt->dst.dev,
 					       rt_nexthop(rt, iph->daddr),
@@ -1354,9 +1358,9 @@ static struct fib_nh_exception *find_exception(struct fib_nh *nh, __be32 daddr)
 
 u32 ip_mtu_from_fib_result(struct fib_result *res, __be32 daddr)
 {
+	struct fib_nh_common *nhc = res->nhc;
+	struct net_device *dev = nhc->nhc_dev;
 	struct fib_info *fi = res->fi;
-	struct fib_nh *nh = &fi->fib_nh[res->nh_sel];
-	struct net_device *dev = nh->fib_nh_dev;
 	u32 mtu = 0;
 
 	if (dev_net(dev)->ipv4.sysctl_ip_fwd_use_pmtu ||
@@ -1364,6 +1368,7 @@ u32 ip_mtu_from_fib_result(struct fib_result *res, __be32 daddr)
 		mtu = fi->fib_mtu;
 
 	if (likely(!mtu)) {
+		struct fib_nh *nh = container_of(nhc, struct fib_nh, nh_common);
 		struct fib_nh_exception *fnhe;
 
 		fnhe = find_exception(nh, daddr);
@@ -1374,7 +1379,7 @@ u32 ip_mtu_from_fib_result(struct fib_result *res, __be32 daddr)
 	if (likely(!mtu))
 		mtu = min(READ_ONCE(dev->mtu), IP_MAX_MTU);
 
-	return mtu - lwtunnel_headroom(nh->fib_nh_lws, mtu);
+	return mtu - lwtunnel_headroom(nhc->nhc_lwtstate, mtu);
 }
 
 static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe,
@@ -1529,7 +1534,8 @@ static void rt_set_nexthop(struct rtable *rt, __be32 daddr,
 	bool cached = false;
 
 	if (fi) {
-		struct fib_nh *nh = &FIB_RES_NH(*res);
+		struct fib_nh_common *nhc = FIB_RES_NHC(*res);
+		struct fib_nh *nh = container_of(nhc, struct fib_nh, nh_common);
 
 		if (nh->fib_nh_gw4 && nh->fib_nh_scope == RT_SCOPE_LINK) {
 			rt->rt_gateway = nh->fib_nh_gw4;
@@ -1699,15 +1705,18 @@ static int __mkroute_input(struct sk_buff *skb,
 			   struct in_device *in_dev,
 			   __be32 daddr, __be32 saddr, u32 tos)
 {
+	struct fib_nh_common *nhc = FIB_RES_NHC(*res);
+	struct net_device *dev = nhc->nhc_dev;
 	struct fib_nh_exception *fnhe;
 	struct rtable *rth;
+	struct fib_nh *nh;
 	int err;
 	struct in_device *out_dev;
 	bool do_cache;
 	u32 itag = 0;
 
 	/* get a working reference to the output device */
-	out_dev = __in_dev_get_rcu(FIB_RES_DEV(*res));
+	out_dev = __in_dev_get_rcu(dev);
 	if (!out_dev) {
 		net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n");
 		return -EINVAL;
@@ -1724,10 +1733,13 @@ static int __mkroute_input(struct sk_buff *skb,
 
 	do_cache = res->fi && !itag;
 	if (out_dev == in_dev && err && IN_DEV_TX_REDIRECTS(out_dev) &&
-	    skb->protocol == htons(ETH_P_IP) &&
-	    (IN_DEV_SHARED_MEDIA(out_dev) ||
-	     inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res))))
-		IPCB(skb)->flags |= IPSKB_DOREDIRECT;
+	    skb->protocol == htons(ETH_P_IP)) {
+		__be32 gw = nhc->nhc_family == AF_INET ? nhc->nhc_gw.ipv4 : 0;
+
+		if (IN_DEV_SHARED_MEDIA(out_dev) ||
+		    inet_addr_onlink(out_dev, saddr, gw))
+			IPCB(skb)->flags |= IPSKB_DOREDIRECT;
+	}
 
 	if (skb->protocol != htons(ETH_P_IP)) {
 		/* Not IP (i.e. ARP). Do not create route, if it is
@@ -1744,12 +1756,13 @@ static int __mkroute_input(struct sk_buff *skb,
 		}
 	}
 
-	fnhe = find_exception(&FIB_RES_NH(*res), daddr);
+	nh = container_of(nhc, struct fib_nh, nh_common);
+	fnhe = find_exception(nh, daddr);
 	if (do_cache) {
 		if (fnhe)
 			rth = rcu_dereference(fnhe->fnhe_rth_input);
 		else
-			rth = rcu_dereference(FIB_RES_NH(*res).nh_rth_input);
+			rth = rcu_dereference(nh->nh_rth_input);
 		if (rt_cache_valid(rth)) {
 			skb_dst_set_noref(skb, &rth->dst);
 			goto out;
@@ -2043,7 +2056,11 @@ out:	return err;
 	do_cache = false;
 	if (res->fi) {
 		if (!itag) {
-			rth = rcu_dereference(FIB_RES_NH(*res).nh_rth_input);
+			struct fib_nh_common *nhc = FIB_RES_NHC(*res);
+			struct fib_nh *nh;
+
+			nh = container_of(nhc, struct fib_nh, nh_common);
+			rth = rcu_dereference(nh->nh_rth_input);
 			if (rt_cache_valid(rth)) {
 				skb_dst_set_noref(skb, &rth->dst);
 				err = 0;
@@ -2073,15 +2090,17 @@ out:	return err;
 	}
 
 	if (do_cache) {
-		struct fib_nh *nh = &FIB_RES_NH(*res);
+		struct fib_nh_common *nhc = FIB_RES_NHC(*res);
+		struct fib_nh *nh;
 
-		rth->dst.lwtstate = lwtstate_get(nh->fib_nh_lws);
+		rth->dst.lwtstate = lwtstate_get(nhc->nhc_lwtstate);
 		if (lwtunnel_input_redirect(rth->dst.lwtstate)) {
 			WARN_ON(rth->dst.input == lwtunnel_input);
 			rth->dst.lwtstate->orig_input = rth->dst.input;
 			rth->dst.input = lwtunnel_input;
 		}
 
+		nh = container_of(nhc, struct fib_nh, nh_common);
 		if (unlikely(!rt_cache_route(nh, rth)))
 			rt_add_uncached_list(rth);
 	}
@@ -2253,8 +2272,9 @@ static struct rtable *__mkroute_output(const struct fib_result *res,
 	fnhe = NULL;
 	do_cache &= fi != NULL;
 	if (fi) {
+		struct fib_nh_common *nhc = FIB_RES_NHC(*res);
+		struct fib_nh *nh = container_of(nhc, struct fib_nh, nh_common);
 		struct rtable __rcu **prth;
-		struct fib_nh *nh = &FIB_RES_NH(*res);
 
 		fnhe = find_exception(nh, fl4->daddr);
 		if (!do_cache)
@@ -2264,8 +2284,8 @@ static struct rtable *__mkroute_output(const struct fib_result *res,
 		} else {
 			if (unlikely(fl4->flowi4_flags &
 				     FLOWI_FLAG_KNOWN_NH &&
-				     !(nh->fib_nh_gw4 &&
-				       nh->fib_nh_scope == RT_SCOPE_LINK))) {
+				     !(nhc->nhc_has_gw &&
+				       nhc->nhc_scope == RT_SCOPE_LINK))) {
 				do_cache = false;
 				goto add;
 			}
-- 
2.11.0

[PATCH v4 net-next 3/5] ipv4: Refactor nexthop attributes in fib_dump_info

[David Ahern]

From: David Ahern <dsahern@gmail.com>

Similar to ipv6, move addition of nexthop attributes to dump
message into helpers that are called for both single path and
multipath routes. Align the new helpers to the IPv6 variant
which most notably means computing the flags argument based on
settings in nh_flags.

The RTA_FLOW argument is unique to IPv4, so it is appended after
the new fib_nexthop_info helper. The intent of a later patch is to
make both fib_nexthop_info and fib_add_nexthop usable for both IPv4
and IPv6. This patch is stepping stone in that direction.

Signed-off-by: David Ahern <dsahern@gmail.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
---
 net/ipv4/fib_semantics.c | 166 ++++++++++++++++++++++++++++++-----------------
 1 file changed, 107 insertions(+), 59 deletions(-)

diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c
index 42666a409da0..32fb0123d881 100644
--- a/net/ipv4/fib_semantics.c
+++ b/net/ipv4/fib_semantics.c
@@ -1317,6 +1317,103 @@ 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,
+			    unsigned int *flags, bool skip_oif)
+{
+	if (nh->fib_nh_flags & RTNH_F_DEAD)
+		*flags |= RTNH_F_DEAD;
+
+	if (nh->fib_nh_flags & RTNH_F_LINKDOWN) {
+		*flags |= RTNH_F_LINKDOWN;
+
+		rcu_read_lock();
+		if (ip_ignore_linkdown(nh->fib_nh_dev))
+			*flags |= RTNH_F_DEAD;
+		rcu_read_unlock();
+	}
+
+	if (nh->fib_nh_gw4 &&
+	    nla_put_in_addr(skb, RTA_GATEWAY, nh->fib_nh_gw4))
+		goto nla_put_failure;
+
+	*flags |= (nh->fib_nh_flags & RTNH_F_ONLINK);
+	if (nh->fib_nh_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))
+		goto nla_put_failure;
+
+	if (nh->fib_nh_lws &&
+	    lwtunnel_fill_encap(skb, nh->fib_nh_lws) < 0)
+		goto nla_put_failure;
+
+	return 0;
+
+nla_put_failure:
+	return -EMSGSIZE;
+}
+
+#ifdef CONFIG_IP_ROUTE_MULTIPATH
+static int fib_add_nexthop(struct sk_buff *skb, const struct fib_nh *nh)
+{
+	const struct net_device *dev = 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 = nh->fib_nh_weight - 1;
+	rtnh->rtnh_ifindex = dev ? dev->ifindex : 0;
+
+	if (fib_nexthop_info(skb, 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 fib_add_multipath(struct sk_buff *skb, struct fib_info *fi)
+{
+	struct nlattr *mp;
+
+	mp = nla_nest_start(skb, RTA_MULTIPATH);
+	if (!mp)
+		goto nla_put_failure;
+
+	for_nexthops(fi) {
+		if (fib_add_nexthop(skb, nh) < 0)
+			goto nla_put_failure;
+#ifdef CONFIG_IP_ROUTE_CLASSID
+		if (nh->nh_tclassid &&
+		    nla_put_u32(skb, RTA_FLOW, nh->nh_tclassid))
+			goto nla_put_failure;
+#endif
+	} endfor_nexthops(fi);
+
+	nla_nest_end(skb, mp);
+
+	return 0;
+
+nla_put_failure:
+	return -EMSGSIZE;
+}
+#else
+static int fib_add_multipath(struct sk_buff *skb, struct fib_info *fi)
+{
+	return 0;
+}
+#endif
+
 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)
@@ -1357,72 +1454,23 @@ int fib_dump_info(struct sk_buff *skb, u32 portid, u32 seq, int event,
 	    nla_put_in_addr(skb, RTA_PREFSRC, fi->fib_prefsrc))
 		goto nla_put_failure;
 	if (fi->fib_nhs == 1) {
-		if (fi->fib_nh->fib_nh_gw4 &&
-		    nla_put_in_addr(skb, RTA_GATEWAY, fi->fib_nh->fib_nh_gw4))
-			goto nla_put_failure;
-		if (fi->fib_nh->fib_nh_oif &&
-		    nla_put_u32(skb, RTA_OIF, fi->fib_nh->fib_nh_oif))
+		struct fib_nh *nh = &fi->fib_nh[0];
+		unsigned int flags = 0;
+
+		if (fib_nexthop_info(skb, nh, &flags, false) < 0)
 			goto nla_put_failure;
-		if (fi->fib_nh->fib_nh_flags & RTNH_F_LINKDOWN) {
-			rcu_read_lock();
-			if (ip_ignore_linkdown(fi->fib_nh->fib_nh_dev))
-				rtm->rtm_flags |= RTNH_F_DEAD;
-			rcu_read_unlock();
-		}
-		if (fi->fib_nh->fib_nh_flags & RTNH_F_OFFLOAD)
-			rtm->rtm_flags |= RTNH_F_OFFLOAD;
+
+		rtm->rtm_flags = flags;
 #ifdef CONFIG_IP_ROUTE_CLASSID
-		if (fi->fib_nh[0].nh_tclassid &&
-		    nla_put_u32(skb, RTA_FLOW, fi->fib_nh[0].nh_tclassid))
+		if (nh->nh_tclassid &&
+		    nla_put_u32(skb, RTA_FLOW, nh->nh_tclassid))
 			goto nla_put_failure;
 #endif
-		if (fi->fib_nh->fib_nh_lws &&
-		    lwtunnel_fill_encap(skb, fi->fib_nh->fib_nh_lws) < 0)
+	} else {
+		if (fib_add_multipath(skb, fi) < 0)
 			goto nla_put_failure;
 	}
-#ifdef CONFIG_IP_ROUTE_MULTIPATH
-	if (fi->fib_nhs > 1) {
-		struct rtnexthop *rtnh;
-		struct nlattr *mp;
-
-		mp = nla_nest_start(skb, RTA_MULTIPATH);
-		if (!mp)
-			goto nla_put_failure;
 
-		for_nexthops(fi) {
-			rtnh = nla_reserve_nohdr(skb, sizeof(*rtnh));
-			if (!rtnh)
-				goto nla_put_failure;
-
-			rtnh->rtnh_flags = nh->fib_nh_flags & 0xFF;
-			if (nh->fib_nh_flags & RTNH_F_LINKDOWN) {
-				rcu_read_lock();
-				if (ip_ignore_linkdown(nh->fib_nh_dev))
-					rtnh->rtnh_flags |= RTNH_F_DEAD;
-				rcu_read_unlock();
-			}
-			rtnh->rtnh_hops = nh->fib_nh_weight - 1;
-			rtnh->rtnh_ifindex = nh->fib_nh_oif;
-
-			if (nh->fib_nh_gw4 &&
-			    nla_put_in_addr(skb, RTA_GATEWAY, nh->fib_nh_gw4))
-				goto nla_put_failure;
-#ifdef CONFIG_IP_ROUTE_CLASSID
-			if (nh->nh_tclassid &&
-			    nla_put_u32(skb, RTA_FLOW, nh->nh_tclassid))
-				goto nla_put_failure;
-#endif
-			if (nh->fib_nh_lws &&
-			    lwtunnel_fill_encap(skb, nh->fib_nh_lws) < 0)
-				goto nla_put_failure;
-
-			/* length of rtnetlink header + attributes */
-			rtnh->rtnh_len = nlmsg_get_pos(skb) - (void *) rtnh;
-		} endfor_nexthops(fi);
-
-		nla_nest_end(skb, mp);
-	}
-#endif
 	nlmsg_end(skb, nlh);
 	return 0;
 
-- 
2.11.0

[PATCH v4 net-next 4/5] ipv4: Change fib_nexthop_info and fib_add_nexthop to take fib_nh_common

[David Ahern]

From: David Ahern <dsahern@gmail.com>

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>
---
 net/ipv4/fib_semantics.c | 52 +++++++++++++++++++++++++++++-------------------
 1 file changed, 32 insertions(+), 20 deletions(-)

diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c
index 32fb0123d881..33a43965a232 100644
--- a/net/ipv4/fib_semantics.c
+++ b/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))
-			*flags |= RTNH_F_DEAD;
+		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))
-		goto nla_put_failure;
+	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;
-- 
2.11.0

[PATCH v4 net-next 5/5] ipv6: Flip to fib_nexthop_info

[David Ahern]

From: David Ahern <dsahern@gmail.com>

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>
---
 include/net/ip_fib.h     |  5 ++++
 net/ipv4/fib_semantics.c | 22 ++++++++++----
 net/ipv6/route.c         | 77 ++++--------------------------------------------
 3 files changed, 28 insertions(+), 76 deletions(-)

diff --git a/include/net/ip_fib.h b/include/net/ip_fib.h
index 1f4a3b8bf584..3ce07841dc3b 100644
--- a/include/net/ip_fib.h
+++ b/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 */
diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c
index 33a43965a232..8e0cb1687a74 100644
--- a/net/ipv4/fib_semantics.c
+++ b/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"
 
@@ -1317,8 +1318,8 @@ 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,
-			    unsigned int *flags, bool skip_oif)
+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)
 		*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;
 		}
 	}
 
@@ -1362,10 +1372,11 @@ 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,
-			   int nh_weight)
+#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;
 	struct rtnexthop *rtnh;
@@ -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
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index e0ee30cbd079..6e89151693d0 100644
--- a/net/ipv6/route.c
+++ b/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;
 	}
 
-- 
2.11.0

Re: [PATCH v4 net-next 0/5] net: More movement to fib_nh_common

[Martin Lau]

On Tue, Apr 02, 2019 at 02:11:53PM -0700, David Ahern wrote:
> From: David Ahern <dsahern@gmail.com>
> 
> Second set of three with the end goal of enabling IPv6 gateways with IPv4
> routes.
I am still not completely convinced on the new "*nhc" in patch 2 without
seeing a patch showing why nh_sel is not enough.

However, since it seems guaranteed that it will be needed soon, for this set,

Acked-by: Martin KaFai Lau <kafai@fb.com>

Re: [PATCH v4 net-next 0/5] net: More movement to fib_nh_common

[David Ahern]

On 4/2/19 11:27 PM, Martin Lau wrote:
> On Tue, Apr 02, 2019 at 02:11:53PM -0700, David Ahern wrote:
>> From: David Ahern <dsahern@gmail.com>
>>
>> Second set of three with the end goal of enabling IPv6 gateways with IPv4
>> routes.
> I am still not completely convinced on the new "*nhc" in patch 2 without
> seeing a patch showing why nh_sel is not enough.

fib_table_lookup and fib_select_path have determined the address of the
preferred fib_nh struct. To look it up again will get costly for nexthop
groups: dereference the nexthop pointer, see that it is a group, get the
pointer to the group data, find the Nth (nh_sel) entry and return it.
Since we already have the end pointer, avoid repeated lookups which
nh_sel requires and save the fib_nh to fib_result. That's what patch 2
is doing and the updated commit message shows that.

Re: [PATCH v4 net-next 0/5] net: More movement to fib_nh_common

[David Miller]

From: David Ahern <dsahern@kernel.org>
Date: Tue,  2 Apr 2019 14:11:53 -0700

> From: David Ahern <dsahern@gmail.com>
> 
> Second set of three with the end goal of enabling IPv6 gateways with IPv4
> routes.
> 
> This set moves:
> - the ipv4 tracepoint to take a fib_nh_common and updates it to handle
>   a v6 gateway.
> - consolidates route notifications to use the same fill functions
>   for both ipv4 and ipv6
 ...

Series applied, thanks David.

Re: [PATCH v4 net-next 0/5] net: More movement to fib_nh_common

[David Ahern]

On 4/3/19 10:50 PM, David Miller wrote:
> From: David Ahern <dsahern@kernel.org>
> Date: Tue,  2 Apr 2019 14:11:53 -0700
> 
>> From: David Ahern <dsahern@gmail.com>
>>
>> Second set of three with the end goal of enabling IPv6 gateways with IPv4
>> routes.
>>
>> This set moves:
>> - the ipv4 tracepoint to take a fib_nh_common and updates it to handle
>>   a v6 gateway.
>> - consolidates route notifications to use the same fill functions
>>   for both ipv4 and ipv6
>  ...
> 
> Series applied, thanks David.
> 

Hi Dave: Have you pushed the changes out? not seeing them on git.kernel.org

Re: [PATCH v4 net-next 0/5] net: More movement to fib_nh_common

[David Miller]

From: David Ahern <dsahern@gmail.com>
Date: Thu, 4 Apr 2019 09:07:04 -0600

> On 4/3/19 10:50 PM, David Miller wrote:
>> From: David Ahern <dsahern@kernel.org>
>> Date: Tue,  2 Apr 2019 14:11:53 -0700
>> 
>>> From: David Ahern <dsahern@gmail.com>
>>>
>>> Second set of three with the end goal of enabling IPv6 gateways with IPv4
>>> routes.
>>>
>>> This set moves:
>>> - the ipv4 tracepoint to take a fib_nh_common and updates it to handle
>>>   a v6 gateway.
>>> - consolidates route notifications to use the same fill functions
>>>   for both ipv4 and ipv6
>>  ...
>> 
>> Series applied, thanks David.
>> 
> 
> Hi Dave: Have you pushed the changes out? not seeing them on git.kernel.org

Should be there now.