net: make skb_gso_*_seglen functions private

They're very hard to use properly as they do not consider the
GSO_BY_FRAGS case. Code should use skb_gso_validate_network_len
and skb_gso_validate_mac_len as they do consider this case.

Make the seglen functions static, which stops people using them
outside of skbuff.c

Signed-off-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/skbuff.h

@@ -3285,7 +3285,6 @@ int skb_zerocopy(struct sk_buff *to, struct sk_buff *from,
 void skb_split(struct sk_buff *skb, struct sk_buff *skb1, const u32 len);
 int skb_shift(struct sk_buff *tgt, struct sk_buff *skb, int shiftlen);
 void skb_scrub_packet(struct sk_buff *skb, bool xnet);
-unsigned int skb_gso_transport_seglen(const struct sk_buff *skb);
 bool skb_gso_validate_network_len(const struct sk_buff *skb, unsigned int mtu);
 bool skb_gso_validate_mac_len(const struct sk_buff *skb, unsigned int len);
 struct sk_buff *skb_segment(struct sk_buff *skb, netdev_features_t features);
@@ -4104,38 +4103,6 @@ static inline bool skb_head_is_locked(const struct sk_buff *skb)
 	return !skb->head_frag || skb_cloned(skb);
 }
 
-/**
- * skb_gso_network_seglen - Return length of individual segments of a gso packet
- *
- * @skb: GSO skb
- *
- * skb_gso_network_seglen is used to determine the real size of the
- * individual segments, including Layer3 (IP, IPv6) and L4 headers (TCP/UDP).
- *
- * The MAC/L2 header is not accounted for.
- */
-static inline unsigned int skb_gso_network_seglen(const struct sk_buff *skb)
-{
-	unsigned int hdr_len = skb_transport_header(skb) -
-			       skb_network_header(skb);
-	return hdr_len + skb_gso_transport_seglen(skb);
-}
-
-/**
- * skb_gso_mac_seglen - Return length of individual segments of a gso packet
- *
- * @skb: GSO skb
- *
- * skb_gso_mac_seglen is used to determine the real size of the
- * individual segments, including MAC/L2, Layer3 (IP, IPv6) and L4
- * headers (TCP/UDP).
- */
-static inline unsigned int skb_gso_mac_seglen(const struct sk_buff *skb)
-{
-	unsigned int hdr_len = skb_transport_header(skb) - skb_mac_header(skb);
-	return hdr_len + skb_gso_transport_seglen(skb);
-}
-
 /* Local Checksum Offload.
  * Compute outer checksum based on the assumption that the
  * inner checksum will be offloaded later.

net/core/skbuff.c

@@ -4891,7 +4891,7 @@ EXPORT_SYMBOL_GPL(skb_scrub_packet);
  *
  * The MAC/L2 or network (IP, IPv6) headers are not accounted for.
  */
-unsigned int skb_gso_transport_seglen(const struct sk_buff *skb)
+static unsigned int skb_gso_transport_seglen(const struct sk_buff *skb)
 {
 	const struct skb_shared_info *shinfo = skb_shinfo(skb);
 	unsigned int thlen = 0;
@@ -4913,7 +4913,40 @@ unsigned int skb_gso_transport_seglen(const struct sk_buff *skb)
 	 */
 	return thlen + shinfo->gso_size;
 }
-EXPORT_SYMBOL_GPL(skb_gso_transport_seglen);
+
+/**
+ * skb_gso_network_seglen - Return length of individual segments of a gso packet
+ *
+ * @skb: GSO skb
+ *
+ * skb_gso_network_seglen is used to determine the real size of the
+ * individual segments, including Layer3 (IP, IPv6) and L4 headers (TCP/UDP).
+ *
+ * The MAC/L2 header is not accounted for.
+ */
+static unsigned int skb_gso_network_seglen(const struct sk_buff *skb)
+{
+	unsigned int hdr_len = skb_transport_header(skb) -
+			       skb_network_header(skb);
+
+	return hdr_len + skb_gso_transport_seglen(skb);
+}
+
+/**
+ * skb_gso_mac_seglen - Return length of individual segments of a gso packet
+ *
+ * @skb: GSO skb
+ *
+ * skb_gso_mac_seglen is used to determine the real size of the
+ * individual segments, including MAC/L2, Layer3 (IP, IPv6) and L4
+ * headers (TCP/UDP).
+ */
+static unsigned int skb_gso_mac_seglen(const struct sk_buff *skb)
+{
+	unsigned int hdr_len = skb_transport_header(skb) - skb_mac_header(skb);
+
+	return hdr_len + skb_gso_transport_seglen(skb);
+}
 
 /**
  * skb_gso_size_check - check the skb size, considering GSO_BY_FRAGS