tcp6: Add GRO support

This patch adds GRO support for TCP over IPv6.  The code is exactly
the same as the IPv4 version except for the pseudo-header checksum
computation.

Note that I've removed the unused tcphdr argument from tcp_v6_check
rather than invent a bogus value for GRO.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 43 insertions, 4 deletions

diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 35bcddf8a932..bd6ff907d9e4 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -2542,6 +2542,7 @@ out:
 
         return pp;
 }
+EXPORT_SYMBOL(tcp_gro_receive);
 
 int tcp_gro_complete(struct sk_buff *skb)
 {
@@ -2558,6 +2559,7 @@ int tcp_gro_complete(struct sk_buff *skb)
 
         return 0;
 }
+EXPORT_SYMBOL(tcp_gro_complete);
 
 #ifdef CONFIG_TCP_MD5SIG
 static unsigned long tcp_md5sig_users;
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index e8b8337a8310..1297306d729c 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -101,7 +101,7 @@ static void tcp_v6_hash(struct sock *sk)
         }
 }
 
-static __inline__ __sum16 tcp_v6_check(struct tcphdr *th, int len,
+static __inline__ __sum16 tcp_v6_check(int len,
                                    struct in6_addr *saddr,
                                    struct in6_addr *daddr,
                                    __wsum base)
@@ -501,7 +501,7 @@ static int tcp_v6_send_synack(struct sock *sk, struct request_sock *req)
         if (skb) {
                 struct tcphdr *th = tcp_hdr(skb);
 
-                th->check = tcp_v6_check(th, skb->len,
+                th->check = tcp_v6_check(skb->len,
                                          &treq->loc_addr, &treq->rmt_addr,
                                          csum_partial(th, skb->len, skb->csum));
 
@@ -942,6 +942,41 @@ static int tcp_v6_gso_send_check(struct sk_buff *skb)
         return 0;
 }
 
+struct sk_buff **tcp6_gro_receive(struct sk_buff **head, struct sk_buff *skb)
+{
+        struct ipv6hdr *iph = ipv6_hdr(skb);
+
+        switch (skb->ip_summed) {
+        case CHECKSUM_COMPLETE:
+                if (!tcp_v6_check(skb->len, &iph->saddr, &iph->daddr,
+                                  skb->csum)) {
+                        skb->ip_summed = CHECKSUM_UNNECESSARY;
+                        break;
+                }
+
+                /* fall through */
+        case CHECKSUM_NONE:
+                NAPI_GRO_CB(skb)->flush = 1;
+                return NULL;
+        }
+
+        return tcp_gro_receive(head, skb);
+}
+EXPORT_SYMBOL(tcp6_gro_receive);
+
+int tcp6_gro_complete(struct sk_buff *skb)
+{
+        struct ipv6hdr *iph = ipv6_hdr(skb);
+        struct tcphdr *th = tcp_hdr(skb);
+
+        th->check = ~tcp_v6_check(skb->len - skb_transport_offset(skb),
+                                  &iph->saddr, &iph->daddr, 0);
+        skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
+
+        return tcp_gro_complete(skb);
+}
+EXPORT_SYMBOL(tcp6_gro_complete);
+
 static void tcp_v6_send_response(struct sk_buff *skb, u32 seq, u32 ack, u32 win,
                                  u32 ts, struct tcp_md5sig_key *key, int rst)
 {
@@ -1429,14 +1464,14 @@ out:
 static __sum16 tcp_v6_checksum_init(struct sk_buff *skb)
 {
         if (skb->ip_summed == CHECKSUM_COMPLETE) {
-                if (!tcp_v6_check(tcp_hdr(skb), skb->len, &ipv6_hdr(skb)->saddr,
+                if (!tcp_v6_check(skb->len, &ipv6_hdr(skb)->saddr,
                                   &ipv6_hdr(skb)->daddr, skb->csum)) {
                         skb->ip_summed = CHECKSUM_UNNECESSARY;
                         return 0;
                 }
         }
 
-        skb->csum = ~csum_unfold(tcp_v6_check(tcp_hdr(skb), skb->len,
+        skb->csum = ~csum_unfold(tcp_v6_check(skb->len,
                                               &ipv6_hdr(skb)->saddr,
                                               &ipv6_hdr(skb)->daddr, 0));
 
@@ -2062,6 +2097,8 @@ static struct inet6_protocol tcpv6_protocol = {
         .err_handler    =       tcp_v6_err,
         .gso_send_check =       tcp_v6_gso_send_check,
         .gso_segment    =       tcp_tso_segment,
+        .gro_receive    =       tcp6_gro_receive,
+        .gro_complete   =       tcp6_gro_complete,
         .flags          =       INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
 };