gro: Clean up tcpX_gro_receive checksum verification

This patch simplifies the checksum verification in tcpX_gro_receive
by reusing the CHECKSUM_COMPLETE code for CHECKSUM_NONE.  All it
does for CHECKSUM_NONE is compute the partial checksum and then
treat it as if it came from the hardware (CHECKSUM_COMPLETE).

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Cheers,
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 55aeec9..0560635 100644 (file)
--- a/net/ipv4/tcp_offload.c
+++ b/net/ipv4/tcp_offload.c
@@ -274,35 +274,29 @@ static struct sk_buff **tcp4_gro_receive(struct sk_buff **head, struct sk_buff *
 {
        const struct iphdr *iph = skb_gro_network_header(skb);
        __wsum wsum;
-       __sum16 sum;
 
        /* Don't bother verifying checksum if we're going to flush anyway. */
        if (NAPI_GRO_CB(skb)->flush)
                goto skip_csum;
 
+       wsum = skb->csum;
+
        switch (skb->ip_summed) {
+       case CHECKSUM_NONE:
+               wsum = skb_checksum(skb, skb_gro_offset(skb), skb_gro_len(skb),
+                                   0);
+
+               /* fall through */
+
        case CHECKSUM_COMPLETE:
                if (!tcp_v4_check(skb_gro_len(skb), iph->saddr, iph->daddr,
-                                 skb->csum)) {
+                                 wsum)) {
                        skb->ip_summed = CHECKSUM_UNNECESSARY;
                        break;
                }
-flush:
+
                NAPI_GRO_CB(skb)->flush = 1;
                return NULL;
-
-       case CHECKSUM_NONE:
-               wsum = csum_tcpudp_nofold(iph->saddr, iph->daddr,
-                                         skb_gro_len(skb), IPPROTO_TCP, 0);
-               sum = csum_fold(skb_checksum(skb,
-                                            skb_gro_offset(skb),
-                                            skb_gro_len(skb),
-                                            wsum));
-               if (sum)
-                       goto flush;
-
-               skb->ip_summed = CHECKSUM_UNNECESSARY;
-               break;
        }
 
 skip_csum:

diff --git a/net/ipv6/tcpv6_offload.c b/net/ipv6/tcpv6_offload.c
index 71923d1..6d18157 100644 (file)
--- a/net/ipv6/tcpv6_offload.c
+++ b/net/ipv6/tcpv6_offload.c
@@ -37,36 +37,29 @@ static struct sk_buff **tcp6_gro_receive(struct sk_buff **head,
 {
        const struct ipv6hdr *iph = skb_gro_network_header(skb);
        __wsum wsum;
-       __sum16 sum;
 
        /* Don't bother verifying checksum if we're going to flush anyway. */
        if (NAPI_GRO_CB(skb)->flush)
                goto skip_csum;
 
+       wsum = skb->csum;
+
        switch (skb->ip_summed) {
+       case CHECKSUM_NONE:
+               wsum = skb_checksum(skb, skb_gro_offset(skb), skb_gro_len(skb),
+                                   wsum);
+
+               /* fall through */
+
        case CHECKSUM_COMPLETE:
                if (!tcp_v6_check(skb_gro_len(skb), &iph->saddr, &iph->daddr,
-                                 skb->csum)) {
+                                 wsum)) {
                        skb->ip_summed = CHECKSUM_UNNECESSARY;
                        break;
                }
-flush:
+
                NAPI_GRO_CB(skb)->flush = 1;
                return NULL;
-
-       case CHECKSUM_NONE:
-               wsum = ~csum_unfold(csum_ipv6_magic(&iph->saddr, &iph->daddr,
-                                                   skb_gro_len(skb),
-                                                   IPPROTO_TCP, 0));
-               sum = csum_fold(skb_checksum(skb,
-                                            skb_gro_offset(skb),
-                                            skb_gro_len(skb),
-                                            wsum));
-               if (sum)
-                       goto flush;
-
-               skb->ip_summed = CHECKSUM_UNNECESSARY;
-               break;
        }
 
 skip_csum: