From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001
From: André Fabian Silva Delgado <emulatorman@parabola.nu>
Date: Wed, 5 Aug 2015 17:04:01 -0300
Subject: Initial import

---
 net/ipv6/tcpv6_offload.c | 78 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 78 insertions(+)
 create mode 100644 net/ipv6/tcpv6_offload.c

(limited to 'net/ipv6/tcpv6_offload.c')

diff --git a/net/ipv6/tcpv6_offload.c b/net/ipv6/tcpv6_offload.c
new file mode 100644
index 000000000..d883c9204
--- /dev/null
+++ b/net/ipv6/tcpv6_offload.c
@@ -0,0 +1,78 @@
+/*
+ *	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 struct sk_buff **tcp6_gro_receive(struct sk_buff **head,
+					 struct sk_buff *skb)
+{
+	/* Don't bother verifying checksum if we're going to flush anyway. */
+	if (!NAPI_GRO_CB(skb)->flush &&
+	    skb_gro_checksum_validate(skb, IPPROTO_TCP,
+				      ip6_gro_compute_pseudo)) {
+		NAPI_GRO_CB(skb)->flush = 1;
+		return NULL;
+	}
+
+	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 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_segment	=	tcp6_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);
+}
-- 
cgit v1.2.3-54-g00ecf