tcp: move logic out of tcp_v[64]_gso_send_check

In tcp_v[46]_gso_send_check the TCP checksum is initialized to the
pseudo header checksum using __tcp_v[46]_send_check. We can move this
logic into new tcp[46]_gso_segment functions to be done when
ip_summed != CHECKSUM_PARTIAL (ip_summed == CHECKSUM_PARTIAL should be
the common case, possibly always true when taking GSO path). After this
change tcp_v[46]_gso_send_check is no-op.

Signed-off-by: Tom Herbert <therbert@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv4/tcp_offload.c b/net/ipv4/tcp_offload.c
index 7291253..7cd12b0 100644 (file)
--- a/net/ipv4/tcp_offload.c
+++ b/net/ipv4/tcp_offload.c
@@ -29,6 +29,28 @@ static void tcp_gso_tstamp(struct sk_buff *skb, unsigned int ts_seq,
        }
 }
 
+struct sk_buff *tcp4_gso_segment(struct sk_buff *skb,
+                                netdev_features_t features)
+{
+       if (!pskb_may_pull(skb, sizeof(struct tcphdr)))
+               return ERR_PTR(-EINVAL);
+
+       if (unlikely(skb->ip_summed != CHECKSUM_PARTIAL)) {
+               const struct iphdr *iph = ip_hdr(skb);
+               struct tcphdr *th = tcp_hdr(skb);
+
+               /* Set up checksum pseudo header, usually expect stack to
+                * have done this already.
+                */
+
+               th->check = 0;
+               skb->ip_summed = CHECKSUM_PARTIAL;
+               __tcp_v4_send_check(skb, iph->saddr, iph->daddr);
+       }
+
+       return tcp_gso_segment(skb, features);
+}
+
 struct sk_buff *tcp_gso_segment(struct sk_buff *skb,
                                netdev_features_t features)
 {
@@ -44,9 +66,6 @@ struct sk_buff *tcp_gso_segment(struct sk_buff *skb,
        __sum16 newcheck;
        bool ooo_okay, copy_destructor;
 
-       if (!pskb_may_pull(skb, sizeof(*th)))
-               goto out;
-
        th = tcp_hdr(skb);
        thlen = th->doff * 4;
        if (thlen < sizeof(*th))
@@ -271,18 +290,6 @@ EXPORT_SYMBOL(tcp_gro_complete);
 
 static int tcp_v4_gso_send_check(struct sk_buff *skb)
 {
-       const struct iphdr *iph;
-       struct tcphdr *th;
-
-       if (!pskb_may_pull(skb, sizeof(*th)))
-               return -EINVAL;
-
-       iph = ip_hdr(skb);
-       th = tcp_hdr(skb);
-
-       th->check = 0;
-       skb->ip_summed = CHECKSUM_PARTIAL;
-       __tcp_v4_send_check(skb, iph->saddr, iph->daddr);
        return 0;
 }
 
@@ -314,7 +321,7 @@ static int tcp4_gro_complete(struct sk_buff *skb, int thoff)
 static const struct net_offload tcpv4_offload = {
        .callbacks = {
                .gso_send_check =       tcp_v4_gso_send_check,
-               .gso_segment    =       tcp_gso_segment,
+               .gso_segment    =       tcp4_gso_segment,
                .gro_receive    =       tcp4_gro_receive,
                .gro_complete   =       tcp4_gro_complete,
        },

diff --git a/net/ipv6/tcpv6_offload.c b/net/ipv6/tcpv6_offload.c
index dbb3d92..9625315 100644 (file)
--- a/net/ipv6/tcpv6_offload.c
+++ b/net/ipv6/tcpv6_offload.c
@@ -17,18 +17,6 @@
 
 static int tcp_v6_gso_send_check(struct sk_buff *skb)
 {
-       const struct ipv6hdr *ipv6h;
-       struct tcphdr *th;
-
-       if (!pskb_may_pull(skb, sizeof(*th)))
-               return -EINVAL;
-
-       ipv6h = ipv6_hdr(skb);
-       th = tcp_hdr(skb);
-
-       th->check = 0;
-       skb->ip_summed = CHECKSUM_PARTIAL;
-       __tcp_v6_send_check(skb, &ipv6h->saddr, &ipv6h->daddr);
        return 0;
 }
 
@@ -58,10 +46,33 @@ static int tcp6_gro_complete(struct sk_buff *skb, int thoff)
        return tcp_gro_complete(skb);
 }
 
+struct sk_buff *tcp6_gso_segment(struct sk_buff *skb,
+                                netdev_features_t features)
+{
+       struct tcphdr *th;
+
+       if (!pskb_may_pull(skb, sizeof(*th)))
+               return ERR_PTR(-EINVAL);
+
+       if (unlikely(skb->ip_summed != CHECKSUM_PARTIAL)) {
+               const struct ipv6hdr *ipv6h = ipv6_hdr(skb);
+               struct tcphdr *th = tcp_hdr(skb);
+
+               /* Set up pseudo header, usually expect stack to have done
+                * this.
+                */
+
+               th->check = 0;
+               skb->ip_summed = CHECKSUM_PARTIAL;
+               __tcp_v6_send_check(skb, &ipv6h->saddr, &ipv6h->daddr);
+       }
+
+       return tcp_gso_segment(skb, features);
+}
 static const struct net_offload tcpv6_offload = {
        .callbacks = {
                .gso_send_check =       tcp_v6_gso_send_check,
-               .gso_segment    =       tcp_gso_segment,
+               .gso_segment    =       tcp6_gso_segment,
                .gro_receive    =       tcp6_gro_receive,
                .gro_complete   =       tcp6_gro_complete,
        },