ip6_gre: Factor out common ip6gre tunnel match into helper

[PATCH net-next] ip6_gre: Factor out common ip6gre tunnel match into helper

Posted by Yue Haibing 2 months, 2 weeks ago

Extract common ip6gre tunnel match from ip6gre_tunnel_lookup() into new
helper function ip6gre_tunnel_match() to reduces code duplication.

No functional change intended.

Signed-off-by: Yue Haibing <yuehaibing@huawei.com>
---
 net/ipv6/ip6_gre.c | 100 +++++++++++++++------------------------------
 1 file changed, 34 insertions(+), 66 deletions(-)

diff --git a/net/ipv6/ip6_gre.c b/net/ipv6/ip6_gre.c
index a1210fd6404e..74d49dd6124d 100644
--- a/net/ipv6/ip6_gre.c
+++ b/net/ipv6/ip6_gre.c
@@ -111,8 +111,32 @@ static u32 HASH_ADDR(const struct in6_addr *addr)
 #define tunnels_l	tunnels[1]
 #define tunnels_wc	tunnels[0]
 
-/* Given src, dst and key, find appropriate for input tunnel. */
+static bool ip6gre_tunnel_match(struct ip6_tnl *t, int dev_type, int link,
+				int *cand_score, struct ip6_tnl **ret)
+{
+	int score = 0;
+
+	if (t->dev->type != ARPHRD_IP6GRE &&
+	    t->dev->type != dev_type)
+		return false;
+
+	if (t->parms.link != link)
+		score |= 1;
+	if (t->dev->type != dev_type)
+		score |= 2;
+	if (score == 0) {
+		*ret = t;
+		return true;
+	}
+
+	if (score < *cand_score) {
+		*ret = t;
+		*cand_score = score;
+	}
+	return false;
+}
 
+/* Given src, dst and key, find appropriate for input tunnel. */
 static struct ip6_tnl *ip6gre_tunnel_lookup(struct net_device *dev,
 		const struct in6_addr *remote, const struct in6_addr *local,
 		__be32 key, __be16 gre_proto)
@@ -127,8 +151,8 @@ static struct ip6_tnl *ip6gre_tunnel_lookup(struct net_device *dev,
 			gre_proto == htons(ETH_P_ERSPAN) ||
 			gre_proto == htons(ETH_P_ERSPAN2)) ?
 		       ARPHRD_ETHER : ARPHRD_IP6GRE;
-	int score, cand_score = 4;
 	struct net_device *ndev;
+	int cand_score = 4;
 
 	for_each_ip_tunnel_rcu(t, ign->tunnels_r_l[h0 ^ h1]) {
 		if (!ipv6_addr_equal(local, &t->parms.laddr) ||
@@ -137,22 +161,8 @@ static struct ip6_tnl *ip6gre_tunnel_lookup(struct net_device *dev,
 		    !(t->dev->flags & IFF_UP))
 			continue;
 
-		if (t->dev->type != ARPHRD_IP6GRE &&
-		    t->dev->type != dev_type)
-			continue;
-
-		score = 0;
-		if (t->parms.link != link)
-			score |= 1;
-		if (t->dev->type != dev_type)
-			score |= 2;
-		if (score == 0)
-			return t;
-
-		if (score < cand_score) {
-			cand = t;
-			cand_score = score;
-		}
+		if (ip6gre_tunnel_match(t, dev_type, link, &cand_score, &cand))
+			return cand;
 	}
 
 	for_each_ip_tunnel_rcu(t, ign->tunnels_r[h0 ^ h1]) {
@@ -161,22 +171,8 @@ static struct ip6_tnl *ip6gre_tunnel_lookup(struct net_device *dev,
 		    !(t->dev->flags & IFF_UP))
 			continue;
 
-		if (t->dev->type != ARPHRD_IP6GRE &&
-		    t->dev->type != dev_type)
-			continue;
-
-		score = 0;
-		if (t->parms.link != link)
-			score |= 1;
-		if (t->dev->type != dev_type)
-			score |= 2;
-		if (score == 0)
-			return t;
-
-		if (score < cand_score) {
-			cand = t;
-			cand_score = score;
-		}
+		if (ip6gre_tunnel_match(t, dev_type, link, &cand_score, &cand))
+			return cand;
 	}
 
 	for_each_ip_tunnel_rcu(t, ign->tunnels_l[h1]) {
@@ -187,22 +183,8 @@ static struct ip6_tnl *ip6gre_tunnel_lookup(struct net_device *dev,
 		    !(t->dev->flags & IFF_UP))
 			continue;
 
-		if (t->dev->type != ARPHRD_IP6GRE &&
-		    t->dev->type != dev_type)
-			continue;
-
-		score = 0;
-		if (t->parms.link != link)
-			score |= 1;
-		if (t->dev->type != dev_type)
-			score |= 2;
-		if (score == 0)
-			return t;
-
-		if (score < cand_score) {
-			cand = t;
-			cand_score = score;
-		}
+		if (ip6gre_tunnel_match(t, dev_type, link, &cand_score, &cand))
+			return cand;
 	}
 
 	for_each_ip_tunnel_rcu(t, ign->tunnels_wc[h1]) {
@@ -210,22 +192,8 @@ static struct ip6_tnl *ip6gre_tunnel_lookup(struct net_device *dev,
 		    !(t->dev->flags & IFF_UP))
 			continue;
 
-		if (t->dev->type != ARPHRD_IP6GRE &&
-		    t->dev->type != dev_type)
-			continue;
-
-		score = 0;
-		if (t->parms.link != link)
-			score |= 1;
-		if (t->dev->type != dev_type)
-			score |= 2;
-		if (score == 0)
-			return t;
-
-		if (score < cand_score) {
-			cand = t;
-			cand_score = score;
-		}
+		if (ip6gre_tunnel_match(t, dev_type, link, &cand_score, &cand))
+			return cand;
 	}
 
 	if (cand)
-- 
2.34.1

Re: [PATCH net-next] ip6_gre: Factor out common ip6gre tunnel match into helper

Posted by Simon Horman 2 months, 2 weeks ago

On Sat, Jul 19, 2025 at 04:15:51PM +0800, Yue Haibing wrote:
> Extract common ip6gre tunnel match from ip6gre_tunnel_lookup() into new
> helper function ip6gre_tunnel_match() to reduces code duplication.
> 
> No functional change intended.
> 
> Signed-off-by: Yue Haibing <yuehaibing@huawei.com>

Reviewed-by: Simon Horman <horms@kernel.org>

Re: [PATCH net-next] ip6_gre: Factor out common ip6gre tunnel match into helper

Posted by Markus Elfring 2 months, 2 weeks ago

> Extract common ip6gre tunnel match from ip6gre_tunnel_lookup() into new
> helper function ip6gre_tunnel_match() to reduces code duplication.
…

                                           reduce?

…
> +++ b/net/ipv6/ip6_gre.c
> @@ -111,8 +111,32 @@ static u32 HASH_ADDR(const struct in6_addr *addr)
…
-/* Given src, dst and key, find appropriate for input tunnel. */
+static bool ip6gre_tunnel_match(struct ip6_tnl *t, int dev_type, int link,
+				int *cand_score, struct ip6_tnl **ret)
+{
+	int score = 0;
+
+	if (t->dev->type != ARPHRD_IP6GRE &&
+	    t->dev->type != dev_type)
+		return false;
…

May the scope be reduced (behind the input parameter validation)
also for this local variable?

Regards,
Markus