GSO: Add GSO type for fixed IPv4 ID

[mirror_ubuntu-zesty-kernel.git] / net / ipv4 / af_inet.c

diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index 8217cd22f921d1eef025f2cda12bcb7f4b751384..5bbea9a0ce96f0ae52f51e0cbac8839b12d2f1cd 100644 (file)
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -1195,10 +1195,10 @@ EXPORT_SYMBOL(inet_sk_rebuild_header);
 static struct sk_buff *inet_gso_segment(struct sk_buff *skb,
                                        netdev_features_t features)
 {
+       bool udpfrag = false, fixedid = false, encap;
        struct sk_buff *segs = ERR_PTR(-EINVAL);
        const struct net_offload *ops;
        unsigned int offset = 0;
-       bool udpfrag, encap;
        struct iphdr *iph;
        int proto;
        int nhoff;
@@ -1217,6 +1217,7 @@ static struct sk_buff *inet_gso_segment(struct sk_buff *skb,
                       SKB_GSO_TCPV6 |
                       SKB_GSO_UDP_TUNNEL |
                       SKB_GSO_UDP_TUNNEL_CSUM |
+                      SKB_GSO_TCP_FIXEDID |
                       SKB_GSO_TUNNEL_REMCSUM |
                       0)))
                goto out;
@@ -1248,11 +1249,14 @@ static struct sk_buff *inet_gso_segment(struct sk_buff *skb,
 
        segs = ERR_PTR(-EPROTONOSUPPORT);
 
-       if (skb->encapsulation &&
-           skb_shinfo(skb)->gso_type & (SKB_GSO_SIT|SKB_GSO_IPIP))
-               udpfrag = proto == IPPROTO_UDP && encap;
-       else
-               udpfrag = proto == IPPROTO_UDP && !skb->encapsulation;
+       if (!skb->encapsulation || encap) {
+               udpfrag = !!(skb_shinfo(skb)->gso_type & SKB_GSO_UDP);
+               fixedid = !!(skb_shinfo(skb)->gso_type & SKB_GSO_TCP_FIXEDID);
+
+               /* fixed ID is invalid if DF bit is not set */
+               if (fixedid && !(iph->frag_off & htons(IP_DF)))
+                       goto out;
+       }
 
        ops = rcu_dereference(inet_offloads[proto]);
        if (likely(ops && ops->callbacks.gso_segment))
@@ -1265,12 +1269,11 @@ static struct sk_buff *inet_gso_segment(struct sk_buff *skb,
        do {
                iph = (struct iphdr *)(skb_mac_header(skb) + nhoff);
                if (udpfrag) {
-                       iph->id = htons(id);
                        iph->frag_off = htons(offset >> 3);
                        if (skb->next)
                                iph->frag_off |= htons(IP_MF);
                        offset += skb->len - nhoff - ihl;
-               } else {
+               } else if (!fixedid) {
                        iph->id = htons(id++);
                }
                iph->tot_len = htons(skb->len - nhoff);