sk_buff: allow segmenting based on frag sizes

This patch allows segmenting a skb based on its frags sizes instead of based on a fixed value. Signed-off-by: Marcelo Ricardo Leitner <[email protected]> Tested-by: Xin Long <[email protected]> Signed-off-by: David S. Miller <[email protected]>
Fishwaldo · Jun 3, 2016 · 3953c46 · 3953c46
1 parent 57c0565
commit 3953c46
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Showing 2 changed files with 12 additions and 3 deletions.
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
@@ -301,6 +301,11 @@ struct sk_buff;
 #endif
 extern int sysctl_max_skb_frags;
 
+/* Set skb_shinfo(skb)->gso_size to this in case you want skb_segment to
+ * segment using its current segmentation instead.
+ */
+#define GSO_BY_FRAGS	0xFFFF
+
 typedef struct skb_frag_struct skb_frag_t;
 
 struct skb_frag_struct {

diff --git a/net/core/skbuff.c b/net/core/skbuff.c
@@ -3116,9 +3116,13 @@ struct sk_buff *skb_segment(struct sk_buff *head_skb,
 		int hsize;
 		int size;
 
-		len = head_skb->len - offset;
-		if (len > mss)
-			len = mss;
+		if (unlikely(mss == GSO_BY_FRAGS)) {
+			len = list_skb->len;
+		} else {
+			len = head_skb->len - offset;
+			if (len > mss)
+				len = mss;
+		}
 
 		hsize = skb_headlen(head_skb) - offset;
 		if (hsize < 0)