net-gre-gro: Fix a bug that breaks the forwarding path

Fixed a bug that was introduced by my GRE-GRO patch
(bf5a755f5e9186406bbf50f4087100af5bd68e40 net-gre-gro: Add GRE
support to the GRO stack) that breaks the forwarding path
because various GSO related fields were not set. The bug will
cause on the egress path either the GSO code to fail, or a
GRE-TSO capable (NETIF_F_GSO_GRE) NICs to choke. The following
fix has been tested for both cases.

Signed-off-by: H.K. Jerry Chu <hkchu@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

5 files changed, 10 insertions, 2 deletions

diff --git a/net/core/dev.c b/net/core/dev.c
index 7990984ca364..367a586d0c8a 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -4096,6 +4096,8 @@ static void napi_reuse_skb(struct napi_struct *napi, struct sk_buff *skb)
         skb->vlan_tci = 0;
         skb->dev = napi->dev;
         skb->skb_iif = 0;
+        skb->encapsulation = 0;
+        skb_shinfo(skb)->gso_type = 0;
         skb->truesize = SKB_TRUESIZE(skb_end_offset(skb));
 
         napi->skb = skb;
diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index d5e6836cf772..d156b3c5f363 100644
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -1429,6 +1429,9 @@ static int inet_gro_complete(struct sk_buff *skb, int nhoff)
         int proto = iph->protocol;
         int err = -ENOSYS;
 
+        if (skb->encapsulation)
+                skb_set_inner_network_header(skb, nhoff);
+
         csum_replace2(&iph->check, iph->tot_len, newlen);
         iph->tot_len = newlen;
 
diff --git a/net/ipv4/gre_offload.c b/net/ipv4/gre_offload.c
index eb92deb12666..f0bdd47bbbcb 100644
--- a/net/ipv4/gre_offload.c
+++ b/net/ipv4/gre_offload.c
@@ -263,6 +263,9 @@ static int gre_gro_complete(struct sk_buff *skb, int nhoff)
         int err = -ENOENT;
         __be16 type;
 
+        skb->encapsulation = 1;
+        skb_shinfo(skb)->gso_type = SKB_GSO_GRE;
+
         type = greh->protocol;
         if (greh->flags & GRE_KEY)
                 grehlen += GRE_HEADER_SECTION;
diff --git a/net/ipv4/tcp_offload.c b/net/ipv4/tcp_offload.c
index 4e86c59ec7f7..55046ecd083e 100644
--- a/net/ipv4/tcp_offload.c
+++ b/net/ipv4/tcp_offload.c
@@ -309,7 +309,7 @@ static int tcp4_gro_complete(struct sk_buff *skb, int thoff)
 
         th->check = ~tcp_v4_check(skb->len - thoff, iph->saddr,
                                   iph->daddr, 0);
-        skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
+        skb_shinfo(skb)->gso_type |= SKB_GSO_TCPV4;
 
         return tcp_gro_complete(skb);
 }
diff --git a/net/ipv6/tcpv6_offload.c b/net/ipv6/tcpv6_offload.c
index 8517d3cd1aed..01b0ff9a0c2c 100644
--- a/net/ipv6/tcpv6_offload.c
+++ b/net/ipv6/tcpv6_offload.c
@@ -73,7 +73,7 @@ static int tcp6_gro_complete(struct sk_buff *skb, int thoff)
 
         th->check = ~tcp_v6_check(skb->len - thoff, &iph->saddr,
                                   &iph->daddr, 0);
-        skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
+        skb_shinfo(skb)->gso_type |= SKB_GSO_TCPV6;
 
         return tcp_gro_complete(skb);
 }