1 files changed, 23 insertions, 20 deletions

diff --git a/net/ipv4/tcp_offload.c b/net/ipv4/tcp_offload.c
index 773083b7f1e9..5c5964962d0c 100644
--- a/net/ipv4/tcp_offload.c
+++ b/net/ipv4/tcp_offload.c
@@ -83,23 +83,6 @@ struct sk_buff *tcp_gso_segment(struct sk_buff *skb,
 
 	if (skb_gso_ok(skb, features | NETIF_F_GSO_ROBUST)) {
 		/* Packet is from an untrusted source, reset gso_segs. */
-		int type = skb_shinfo(skb)->gso_type;
-
-		if (unlikely(type &
-			     ~(SKB_GSO_TCPV4 |
-			       SKB_GSO_DODGY |
-			       SKB_GSO_TCP_ECN |
-			       SKB_GSO_TCPV6 |
-			       SKB_GSO_GRE |
-			       SKB_GSO_GRE_CSUM |
-			       SKB_GSO_IPIP |
-			       SKB_GSO_SIT |
-			       SKB_GSO_UDP_TUNNEL |
-			       SKB_GSO_UDP_TUNNEL_CSUM |
-			       SKB_GSO_TUNNEL_REMCSUM |
-			       0) ||
-			     !(type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6))))
-			goto out;
 
 		skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(skb->len, mss);
 
@@ -107,6 +90,12 @@ struct sk_buff *tcp_gso_segment(struct sk_buff *skb,
 		goto out;
 	}
 
+	/* GSO partial only requires splitting the frame into an MSS
+	 * multiple and possibly a remainder.  So update the mss now.
+	 */
+	if (features & NETIF_F_GSO_PARTIAL)
+		mss = skb->len - (skb->len % mss);
+
 	copy_destructor = gso_skb->destructor == tcp_wfree;
 	ooo_okay = gso_skb->ooo_okay;
 	/* All segments but the first should have ooo_okay cleared */
@@ -131,7 +120,7 @@ struct sk_buff *tcp_gso_segment(struct sk_buff *skb,
 	newcheck = ~csum_fold((__force __wsum)((__force u32)th->check +
 					       (__force u32)delta));
 
-	do {
+	while (skb->next) {
 		th->fin = th->psh = 0;
 		th->check = newcheck;
 
@@ -151,7 +140,7 @@ struct sk_buff *tcp_gso_segment(struct sk_buff *skb,
 
 		th->seq = htonl(seq);
 		th->cwr = 0;
-	} while (skb->next);
+	}
 
 	/* Following permits TCP Small Queues to work well with GSO :
 	 * The callback to TCP stack will be called at the time last frag
@@ -237,7 +226,7 @@ struct sk_buff **tcp_gro_receive(struct sk_buff **head, struct sk_buff *skb)
 
 found:
 	/* Include the IP ID check below from the inner most IP hdr */
-	flush = NAPI_GRO_CB(p)->flush | NAPI_GRO_CB(p)->flush_id;
+	flush = NAPI_GRO_CB(p)->flush;
 	flush |= (__force int)(flags & TCP_FLAG_CWR);
 	flush |= (__force int)((flags ^ tcp_flag_word(th2)) &
 		  ~(TCP_FLAG_CWR | TCP_FLAG_FIN | TCP_FLAG_PSH));
@@ -246,6 +235,17 @@ found:
 		flush |= *(u32 *)((u8 *)th + i) ^
 			 *(u32 *)((u8 *)th2 + i);
 
+	/* When we receive our second frame we can made a decision on if we
+	 * continue this flow as an atomic flow with a fixed ID or if we use
+	 * an incrementing ID.
+	 */
+	if (NAPI_GRO_CB(p)->flush_id != 1 ||
+	    NAPI_GRO_CB(p)->count != 1 ||
+	    !NAPI_GRO_CB(p)->is_atomic)
+		flush |= NAPI_GRO_CB(p)->flush_id;
+	else
+		NAPI_GRO_CB(p)->is_atomic = false;
+
 	mss = skb_shinfo(p)->gso_size;
 
 	flush |= (len - 1) >= mss;
@@ -314,6 +314,9 @@ static int tcp4_gro_complete(struct sk_buff *skb, int thoff)
 				  iph->daddr, 0);
 	skb_shinfo(skb)->gso_type |= SKB_GSO_TCPV4;
 
+	if (NAPI_GRO_CB(skb)->is_atomic)
+		skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_FIXEDID;
+
 	return tcp_gro_complete(skb);
 }