net: add and use skb_gso_transport_seglen()

[~andy/linux] / net / core / skbuff.c

diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 8f519dbb358b4b8ab8d2f497a000383fe7656341..9ae6d11374d1567cf6f7a9511bc1c48bb8bade81 100644 (file)
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -47,6 +47,8 @@
 #include <linux/in.h>
 #include <linux/inet.h>
 #include <linux/slab.h>
+#include <linux/tcp.h>
+#include <linux/udp.h>
 #include <linux/netdevice.h>
 #ifdef CONFIG_NET_CLS_ACT
 #include <net/pkt_sched.h>
@@ -3916,3 +3918,26 @@ void skb_scrub_packet(struct sk_buff *skb, bool xnet)
        nf_reset_trace(skb);
 }
 EXPORT_SYMBOL_GPL(skb_scrub_packet);
+
+/**
+ * skb_gso_transport_seglen - Return length of individual segments of a gso packet
+ *
+ * @skb: GSO skb
+ *
+ * skb_gso_transport_seglen is used to determine the real size of the
+ * individual segments, including Layer4 headers (TCP/UDP).
+ *
+ * The MAC/L2 or network (IP, IPv6) headers are not accounted for.
+ */
+unsigned int skb_gso_transport_seglen(const struct sk_buff *skb)
+{
+       const struct skb_shared_info *shinfo = skb_shinfo(skb);
+       unsigned int hdr_len;
+
+       if (likely(shinfo->gso_type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6)))
+               hdr_len = tcp_hdrlen(skb);
+       else
+               hdr_len = sizeof(struct udphdr);
+       return hdr_len + shinfo->gso_size;
+}
+EXPORT_SYMBOL_GPL(skb_gso_transport_seglen);