net: selftests: export packet creation helpers for driver use

Export the network selftest packet creation infrastructure to allow
network drivers to reuse the existing selftest framework instead of
duplicating packet creation code.

Signed-off-by: Raju Rangoju <Raju.Rangoju@amd.com>
Reviewed-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Link: https://patch.msgid.link/20251031111811.775434-1-Raju.Rangoju@amd.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

2 files changed, 52 insertions, 41 deletions

diff --git a/include/net/selftests.h b/include/net/selftests.h
index e65e8d230d33..c36e07406ad4 100644
--- a/include/net/selftests.h
+++ b/include/net/selftests.h
@@ -3,9 +3,48 @@
 #define _NET_SELFTESTS
 
 #include <linux/ethtool.h>
+#include <linux/netdevice.h>
+
+struct net_packet_attrs {
+	const unsigned char *src;
+	const unsigned char *dst;
+	u32 ip_src;
+	u32 ip_dst;
+	bool tcp;
+	u16 sport;
+	u16 dport;
+	int timeout;
+	int size;
+	int max_size;
+	u8 id;
+	u16 queue_mapping;
+	bool bad_csum;
+};
+
+struct net_test_priv {
+	struct net_packet_attrs *packet;
+	struct packet_type pt;
+	struct completion comp;
+	int double_vlan;
+	int vlan_id;
+	int ok;
+};
+
+struct netsfhdr {
+	__be32 version;
+	__be64 magic;
+	u8 id;
+} __packed;
+
+#define NET_TEST_PKT_SIZE (sizeof(struct ethhdr) + sizeof(struct iphdr) + \
+			   sizeof(struct netsfhdr))
+#define NET_TEST_PKT_MAGIC	0xdeadcafecafedeadULL
+#define NET_LB_TIMEOUT		msecs_to_jiffies(200)
 
 #if IS_ENABLED(CONFIG_NET_SELFTESTS)
 
+struct sk_buff *net_test_get_skb(struct net_device *ndev, u8 id,
+				 struct net_packet_attrs *attr);
 void net_selftest(struct net_device *ndev, struct ethtool_test *etest,
 		  u64 *buf);
 int net_selftest_get_count(void);
@@ -13,6 +52,12 @@ void net_selftest_get_strings(u8 *data);
 
 #else
 
+static inline struct sk_buff *net_test_get_skb(struct net_device *ndev, u8 id,
+					       struct net_packet_attrs *attr)
+{
+	return NULL;
+}
+
 static inline void net_selftest(struct net_device *ndev, struct ethtool_test *etest,
 				u64 *buf)
 {
diff --git a/net/core/selftests.c b/net/core/selftests.c
index 3d79133a91a6..8b81feb82c4a 100644
--- a/net/core/selftests.c
+++ b/net/core/selftests.c
@@ -14,46 +14,10 @@
 #include <net/tcp.h>
 #include <net/udp.h>
 
-struct net_packet_attrs {
-	const unsigned char *src;
-	const unsigned char *dst;
-	u32 ip_src;
-	u32 ip_dst;
-	bool tcp;
-	u16 sport;
-	u16 dport;
-	int timeout;
-	int size;
-	int max_size;
-	u8 id;
-	u16 queue_mapping;
-	bool bad_csum;
-};
-
-struct net_test_priv {
-	struct net_packet_attrs *packet;
-	struct packet_type pt;
-	struct completion comp;
-	int double_vlan;
-	int vlan_id;
-	int ok;
-};
-
-struct netsfhdr {
-	__be32 version;
-	__be64 magic;
-	u8 id;
-} __packed;
-
 static u8 net_test_next_id;
 
-#define NET_TEST_PKT_SIZE (sizeof(struct ethhdr) + sizeof(struct iphdr) + \
-			   sizeof(struct netsfhdr))
-#define NET_TEST_PKT_MAGIC	0xdeadcafecafedeadULL
-#define NET_LB_TIMEOUT		msecs_to_jiffies(200)
-
-static struct sk_buff *net_test_get_skb(struct net_device *ndev,
-					struct net_packet_attrs *attr)
+struct sk_buff *net_test_get_skb(struct net_device *ndev, u8 id,
+				 struct net_packet_attrs *attr)
 {
 	struct sk_buff *skb = NULL;
 	struct udphdr *uhdr = NULL;
@@ -142,8 +106,8 @@ static struct sk_buff *net_test_get_skb(struct net_device *ndev,
 	shdr = skb_put(skb, sizeof(*shdr));
 	shdr->version = 0;
 	shdr->magic = cpu_to_be64(NET_TEST_PKT_MAGIC);
-	attr->id = net_test_next_id;
-	shdr->id = net_test_next_id++;
+	attr->id = id;
+	shdr->id = id;
 
 	if (attr->size) {
 		void *payload = skb_put(skb, attr->size);
@@ -190,6 +154,7 @@ static struct sk_buff *net_test_get_skb(struct net_device *ndev,
 
 	return skb;
 }
+EXPORT_SYMBOL_GPL(net_test_get_skb);
 
 static int net_test_loopback_validate(struct sk_buff *skb,
 				      struct net_device *ndev,
@@ -286,12 +251,13 @@ static int __net_test_loopback(struct net_device *ndev,
 	tpriv->packet = attr;
 	dev_add_pack(&tpriv->pt);
 
-	skb = net_test_get_skb(ndev, attr);
+	skb = net_test_get_skb(ndev, net_test_next_id, attr);
 	if (!skb) {
 		ret = -ENOMEM;
 		goto cleanup;
 	}
 
+	net_test_next_id++;
 	ret = dev_direct_xmit(skb, attr->queue_mapping);
 	if (ret < 0) {
 		goto cleanup;