mpls: Use in6_dev_rcu() and dev_net_rcu() in mpls_forward() and mpls_xmit().

mpls_forward() and mpls_xmit() are called under RCU.

Let's use in6_dev_rcu() and dev_net_rcu() there to annotate
as such.

Now we pass net to mpls_stats_inc_outucastpkts() not to read
dev_net_rcu() twice.

Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Guillaume Nault <gnault@redhat.com>
Link: https://patch.msgid.link/20251029173344.2934622-6-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

3 files changed, 12 insertions, 10 deletions

diff --git a/net/mpls/af_mpls.c b/net/mpls/af_mpls.c
index c5bbf712f8be..efc6c7da5766 100644
--- a/net/mpls/af_mpls.c
+++ b/net/mpls/af_mpls.c
@@ -129,7 +129,8 @@ bool mpls_pkt_too_big(const struct sk_buff *skb, unsigned int mtu)
 }
 EXPORT_SYMBOL_GPL(mpls_pkt_too_big);
 
-void mpls_stats_inc_outucastpkts(struct net_device *dev,
+void mpls_stats_inc_outucastpkts(struct net *net,
+				 struct net_device *dev,
 				 const struct sk_buff *skb)
 {
 	struct mpls_dev *mdev;
@@ -141,13 +142,13 @@ void mpls_stats_inc_outucastpkts(struct net_device *dev,
 					   tx_packets,
 					   tx_bytes);
 	} else if (skb->protocol == htons(ETH_P_IP)) {
-		IP_UPD_PO_STATS(dev_net(dev), IPSTATS_MIB_OUT, skb->len);
+		IP_UPD_PO_STATS(net, IPSTATS_MIB_OUT, skb->len);
 #if IS_ENABLED(CONFIG_IPV6)
 	} else if (skb->protocol == htons(ETH_P_IPV6)) {
-		struct inet6_dev *in6dev = __in6_dev_get(dev);
+		struct inet6_dev *in6dev = in6_dev_rcu(dev);
 
 		if (in6dev)
-			IP6_UPD_PO_STATS(dev_net(dev), in6dev,
+			IP6_UPD_PO_STATS(net, in6dev,
 					 IPSTATS_MIB_OUT, skb->len);
 #endif
 	}
@@ -342,7 +343,7 @@ static bool mpls_egress(struct net *net, struct mpls_route *rt,
 static int mpls_forward(struct sk_buff *skb, struct net_device *dev,
 			struct packet_type *pt, struct net_device *orig_dev)
 {
-	struct net *net = dev_net(dev);
+	struct net *net = dev_net_rcu(dev);
 	struct mpls_shim_hdr *hdr;
 	const struct mpls_nh *nh;
 	struct mpls_route *rt;
@@ -434,7 +435,7 @@ static int mpls_forward(struct sk_buff *skb, struct net_device *dev,
 	dec.ttl -= 1;
 	if (unlikely(!new_header_size && dec.bos)) {
 		/* Penultimate hop popping */
-		if (!mpls_egress(dev_net(out_dev), rt, skb, dec))
+		if (!mpls_egress(net, rt, skb, dec))
 			goto err;
 	} else {
 		bool bos;
@@ -451,7 +452,7 @@ static int mpls_forward(struct sk_buff *skb, struct net_device *dev,
 		}
 	}
 
-	mpls_stats_inc_outucastpkts(out_dev, skb);
+	mpls_stats_inc_outucastpkts(net, out_dev, skb);
 
 	/* If via wasn't specified then send out using device address */
 	if (nh->nh_via_table == MPLS_NEIGH_TABLE_UNSPEC)
diff --git a/net/mpls/internal.h b/net/mpls/internal.h
index 3a5feca27d6a..e491427ea08a 100644
--- a/net/mpls/internal.h
+++ b/net/mpls/internal.h
@@ -197,7 +197,8 @@ int nla_get_labels(const struct nlattr *nla, u8 max_labels, u8 *labels,
 bool mpls_output_possible(const struct net_device *dev);
 unsigned int mpls_dev_mtu(const struct net_device *dev);
 bool mpls_pkt_too_big(const struct sk_buff *skb, unsigned int mtu);
-void mpls_stats_inc_outucastpkts(struct net_device *dev,
+void mpls_stats_inc_outucastpkts(struct net *net,
+				 struct net_device *dev,
 				 const struct sk_buff *skb);
 
 #endif /* MPLS_INTERNAL_H */
diff --git a/net/mpls/mpls_iptunnel.c b/net/mpls/mpls_iptunnel.c
index 6e73da94af7f..cfbab7b2fec7 100644
--- a/net/mpls/mpls_iptunnel.c
+++ b/net/mpls/mpls_iptunnel.c
@@ -53,7 +53,7 @@ static int mpls_xmit(struct sk_buff *skb)
 
 	/* Find the output device */
 	out_dev = dst->dev;
-	net = dev_net(out_dev);
+	net = dev_net_rcu(out_dev);
 
 	if (!mpls_output_possible(out_dev) ||
 	    !dst->lwtstate || skb_warn_if_lro(skb))
@@ -128,7 +128,7 @@ static int mpls_xmit(struct sk_buff *skb)
 		bos = false;
 	}
 
-	mpls_stats_inc_outucastpkts(out_dev, skb);
+	mpls_stats_inc_outucastpkts(net, out_dev, skb);
 
 	if (rt) {
 		if (rt->rt_gw_family == AF_INET6)