net: common metrics init helper for FIB entries

Consolidate initialization of ipv4 and ipv6 metrics when fib entries
are created into a single helper, ip_fib_metrics_init, that handles
the call to ip_metrics_convert.

If no metrics are defined for the fib entry, then the metrics is set
to dst_default_metrics.

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/ip.h

@@ -420,8 +420,8 @@ static inline unsigned int ip_skb_dst_mtu(struct sock *sk,
 	return min(READ_ONCE(skb_dst(skb)->dev->mtu), IP_MAX_MTU);
 }
 
-int ip_metrics_convert(struct net *net, struct nlattr *fc_mx, int fc_mx_len,
+struct dst_metrics *ip_fib_metrics_init(struct net *net, struct nlattr *fc_mx,
-		       u32 *metrics);
+					int fc_mx_len);
 
 u32 ip_idents_reserve(u32 hash, int segs);
 void __ip_select_ident(struct net *net, struct iphdr *iph, int segs);

net/ipv4/fib_semantics.c

@@ -1020,13 +1020,6 @@ static bool fib_valid_prefsrc(struct fib_config *cfg, __be32 fib_prefsrc)
 	return true;
 }
 
-static int
-fib_convert_metrics(struct fib_info *fi, const struct fib_config *cfg)
-{
-	return ip_metrics_convert(fi->fib_net, cfg->fc_mx, cfg->fc_mx_len,
-				  fi->fib_metrics->metrics);
-}
-
 struct fib_info *fib_create_info(struct fib_config *cfg,
 				 struct netlink_ext_ack *extack)
 {
@@ -1084,16 +1077,14 @@ struct fib_info *fib_create_info(struct fib_config *cfg,
 	fi = kzalloc(sizeof(*fi)+nhs*sizeof(struct fib_nh), GFP_KERNEL);
 	if (!fi)
 		goto failure;
-	if (cfg->fc_mx) {
+	fi->fib_metrics = ip_fib_metrics_init(fi->fib_net, cfg->fc_mx,
-		fi->fib_metrics = kzalloc(sizeof(*fi->fib_metrics), GFP_KERNEL);
+					      cfg->fc_mx_len);
-		if (unlikely(!fi->fib_metrics)) {
+	if (unlikely(IS_ERR(fi->fib_metrics))) {
+		err = PTR_ERR(fi->fib_metrics);
 		kfree(fi);
 		return ERR_PTR(err);
 	}
-		refcount_set(&fi->fib_metrics->refcnt, 1);
+
-	} else {
-		fi->fib_metrics = (struct dst_metrics *)&dst_default_metrics;
-	}
 	fib_info_cnt++;
 	fi->fib_net = net;
 	fi->fib_protocol = cfg->fc_protocol;
@@ -1112,10 +1103,6 @@ struct fib_info *fib_create_info(struct fib_config *cfg,
 			goto failure;
 	} endfor_nexthops(fi)
 
-	err = fib_convert_metrics(fi, cfg);
-	if (err)
-		goto failure;
-
 	if (cfg->fc_mp) {
 #ifdef CONFIG_IP_ROUTE_MULTIPATH
 		err = fib_get_nhs(fi, cfg->fc_mp, cfg->fc_mp_len, cfg, extack);

net/ipv4/metrics.c

@@ -5,8 +5,8 @@
 #include <net/net_namespace.h>
 #include <net/tcp.h>
 
-int ip_metrics_convert(struct net *net, struct nlattr *fc_mx, int fc_mx_len,
+static int ip_metrics_convert(struct net *net, struct nlattr *fc_mx,
-		       u32 *metrics)
+			      int fc_mx_len, u32 *metrics)
 {
 	bool ecn_ca = false;
 	struct nlattr *nla;
@@ -52,4 +52,28 @@ int ip_metrics_convert(struct net *net, struct nlattr *fc_mx, int fc_mx_len,
 
 	return 0;
 }
-EXPORT_SYMBOL_GPL(ip_metrics_convert);
+
+struct dst_metrics *ip_fib_metrics_init(struct net *net, struct nlattr *fc_mx,
+					int fc_mx_len)
+{
+	struct dst_metrics *fib_metrics;
+	int err;
+
+	if (!fc_mx)
+		return (struct dst_metrics *)&dst_default_metrics;
+
+	fib_metrics = kzalloc(sizeof(*fib_metrics), GFP_KERNEL);
+	if (unlikely(!fib_metrics))
+		return ERR_PTR(-ENOMEM);
+
+	err = ip_metrics_convert(net, fc_mx, fc_mx_len, fib_metrics->metrics);
+	if (!err) {
+		refcount_set(&fib_metrics->refcnt, 1);
+	} else {
+		kfree(fib_metrics);
+		fib_metrics = ERR_PTR(err);
+	}
+
+	return fib_metrics;
+}
+EXPORT_SYMBOL_GPL(ip_fib_metrics_init);

net/ipv6/ip6_fib.c

@@ -160,8 +160,6 @@ struct fib6_info *fib6_info_alloc(gfp_t gfp_flags)
 	}
 
 	INIT_LIST_HEAD(&f6i->fib6_siblings);
-	f6i->fib6_metrics = (struct dst_metrics *)&dst_default_metrics;
-
 	atomic_inc(&f6i->fib6_ref);
 
 	return f6i;

net/ipv6/route.c

@@ -2705,24 +2705,6 @@ out:
 	return entries > rt_max_size;
 }
 
-static int ip6_convert_metrics(struct net *net, struct fib6_info *rt,
-			       struct fib6_config *cfg)
-{
-	struct dst_metrics *p;
-
-	if (!cfg->fc_mx)
-		return 0;
-
-	p = kzalloc(sizeof(*rt->fib6_metrics), GFP_KERNEL);
-	if (unlikely(!p))
-		return -ENOMEM;
-
-	refcount_set(&p->refcnt, 1);
-	rt->fib6_metrics = p;
-
-	return ip_metrics_convert(net, cfg->fc_mx, cfg->fc_mx_len, p->metrics);
-}
-
 static struct rt6_info *ip6_nh_lookup_table(struct net *net,
 					    struct fib6_config *cfg,
 					    const struct in6_addr *gw_addr,
@@ -2998,13 +2980,15 @@ static struct fib6_info *ip6_route_info_create(struct fib6_config *cfg,
 	if (!rt)
 		goto out;
 
+	rt->fib6_metrics = ip_fib_metrics_init(net, cfg->fc_mx, cfg->fc_mx_len);
+	if (IS_ERR(rt->fib6_metrics)) {
+		err = PTR_ERR(rt->fib6_metrics);
+		goto out;
+	}
+
 	if (cfg->fc_flags & RTF_ADDRCONF)
 		rt->dst_nocount = true;
 
-	err = ip6_convert_metrics(net, rt, cfg);
-	if (err < 0)
-		goto out;
-
 	if (cfg->fc_flags & RTF_EXPIRES)
 		fib6_set_expires(rt, jiffies +
 				clock_t_to_jiffies(cfg->fc_expires));
@@ -3727,6 +3711,7 @@ struct fib6_info *addrconf_f6i_alloc(struct net *net,
 	if (!f6i)
 		return ERR_PTR(-ENOMEM);
 
+	f6i->fib6_metrics = ip_fib_metrics_init(net, NULL, 0);
 	f6i->dst_nocount = true;
 	f6i->dst_host = true;
 	f6i->fib6_protocol = RTPROT_KERNEL;