1 files changed, 93 insertions, 0 deletions
diff --git a/net/ipv6/tcpv6_offload.c b/net/ipv6/tcpv6_offload.c
new file mode 100644
index 00000000000..01b0ff9a0c2
--- /dev/null
+++ b/net/ipv6/tcpv6_offload.c
@@ -0,0 +1,93 @@
+/*
+ *	IPV6 GSO/GRO offload support
+ *	Linux INET6 implementation
+ *
+ *	This program is free software; you can redistribute it and/or
+ *      modify it under the terms of the GNU General Public License
+ *      as published by the Free Software Foundation; either version
+ *      2 of the License, or (at your option) any later version.
+ *
+ *      TCPv6 GSO/GRO support
+ */
+#include <linux/skbuff.h>
+#include <net/protocol.h>
+#include <net/tcp.h>
+#include <net/ip6_checksum.h>
+#include "ip6_offload.h"
+
+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;
+}
+
+static struct sk_buff **tcp6_gro_receive(struct sk_buff **head,
+					 struct sk_buff *skb)
+{
+	const struct ipv6hdr *iph = skb_gro_network_header(skb);
+	__wsum wsum;
+
+	/* Don't bother verifying checksum if we're going to flush anyway. */
+	if (NAPI_GRO_CB(skb)->flush)
+		goto skip_csum;
+
+	wsum = NAPI_GRO_CB(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,
+				  wsum)) {
+			skb->ip_summed = CHECKSUM_UNNECESSARY;
+			break;
+		}
+
+		NAPI_GRO_CB(skb)->flush = 1;
+		return NULL;
+	}
+
+skip_csum:
+	return tcp_gro_receive(head, skb);
+}
+
+static int tcp6_gro_complete(struct sk_buff *skb, int thoff)
+{
+	const struct ipv6hdr *iph = ipv6_hdr(skb);
+	struct tcphdr *th = tcp_hdr(skb);
+
+	th->check = ~tcp_v6_check(skb->len - thoff, &iph->saddr,
+				  &iph->daddr, 0);
+	skb_shinfo(skb)->gso_type |= SKB_GSO_TCPV6;
+
+	return tcp_gro_complete(skb);
+}
+
+static const struct net_offload tcpv6_offload = {
+	.callbacks = {
+		.gso_send_check	=	tcp_v6_gso_send_check,
+		.gso_segment	=	tcp_gso_segment,
+		.gro_receive	=	tcp6_gro_receive,
+		.gro_complete	=	tcp6_gro_complete,
+	},
+};
+
+int __init tcpv6_offload_init(void)
+{
+	return inet6_add_offload(&tcpv6_offload, IPPROTO_TCP);
+}