1 files changed, 143 insertions, 0 deletions

diff --git a/net/ipv6/xfrm6_output.c b/net/ipv6/xfrm6_output.c
new file mode 100644
index 000000000000..601a148f60f3
--- /dev/null
+++ b/net/ipv6/xfrm6_output.c
@@ -0,0 +1,143 @@
+/*
+ * xfrm6_output.c - Common IPsec encapsulation code for IPv6.
+ * Copyright (C) 2002 USAGI/WIDE Project
+ * Copyright (c) 2004 Herbert Xu <herbert@gondor.apana.org.au>
+ * 
+ * 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.
+ */
+
+#include <linux/skbuff.h>
+#include <linux/spinlock.h>
+#include <linux/icmpv6.h>
+#include <net/dsfield.h>
+#include <net/inet_ecn.h>
+#include <net/ipv6.h>
+#include <net/xfrm.h>
+
+/* Add encapsulation header.
+ *
+ * In transport mode, the IP header and mutable extension headers will be moved
+ * forward to make space for the encapsulation header.
+ *
+ * In tunnel mode, the top IP header will be constructed per RFC 2401.
+ * The following fields in it shall be filled in by x->type->output:
+ *	payload_len
+ *
+ * On exit, skb->h will be set to the start of the encapsulation header to be
+ * filled in by x->type->output and skb->nh will be set to the nextheader field
+ * of the extension header directly preceding the encapsulation header, or in
+ * its absence, that of the top IP header.  The value of skb->data will always
+ * point to the top IP header.
+ */
+static void xfrm6_encap(struct sk_buff *skb)
+{
+	struct dst_entry *dst = skb->dst;
+	struct xfrm_state *x = dst->xfrm;
+	struct ipv6hdr *iph, *top_iph;
+	int dsfield;
+
+	skb_push(skb, x->props.header_len);
+	iph = skb->nh.ipv6h;
+
+	if (!x->props.mode) {
+		u8 *prevhdr;
+		int hdr_len;
+
+		hdr_len = ip6_find_1stfragopt(skb, &prevhdr);
+		skb->nh.raw = prevhdr - x->props.header_len;
+		skb->h.raw = skb->data + hdr_len;
+		memmove(skb->data, iph, hdr_len);
+		return;
+	}
+
+	skb->nh.raw = skb->data;
+	top_iph = skb->nh.ipv6h;
+	skb->nh.raw = &top_iph->nexthdr;
+	skb->h.ipv6h = top_iph + 1;
+
+	top_iph->version = 6;
+	top_iph->priority = iph->priority;
+	top_iph->flow_lbl[0] = iph->flow_lbl[0];
+	top_iph->flow_lbl[1] = iph->flow_lbl[1];
+	top_iph->flow_lbl[2] = iph->flow_lbl[2];
+	dsfield = ipv6_get_dsfield(top_iph);
+	dsfield = INET_ECN_encapsulate(dsfield, dsfield);
+	if (x->props.flags & XFRM_STATE_NOECN)
+		dsfield &= ~INET_ECN_MASK;
+	ipv6_change_dsfield(top_iph, 0, dsfield);
+	top_iph->nexthdr = IPPROTO_IPV6; 
+	top_iph->hop_limit = dst_metric(dst->child, RTAX_HOPLIMIT);
+	ipv6_addr_copy(&top_iph->saddr, (struct in6_addr *)&x->props.saddr);
+	ipv6_addr_copy(&top_iph->daddr, (struct in6_addr *)&x->id.daddr);
+}
+
+static int xfrm6_tunnel_check_size(struct sk_buff *skb)
+{
+	int mtu, ret = 0;
+	struct dst_entry *dst = skb->dst;
+
+	mtu = dst_mtu(dst);
+	if (mtu < IPV6_MIN_MTU)
+		mtu = IPV6_MIN_MTU;
+
+	if (skb->len > mtu) {
+		icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, skb->dev);
+		ret = -EMSGSIZE;
+	}
+
+	return ret;
+}
+
+int xfrm6_output(struct sk_buff *skb)
+{
+	struct dst_entry *dst = skb->dst;
+	struct xfrm_state *x = dst->xfrm;
+	int err;
+	
+	if (skb->ip_summed == CHECKSUM_HW) {
+		err = skb_checksum_help(skb, 0);
+		if (err)
+			goto error_nolock;
+	}
+
+	if (x->props.mode) {
+		err = xfrm6_tunnel_check_size(skb);
+		if (err)
+			goto error_nolock;
+	}
+
+	spin_lock_bh(&x->lock);
+	err = xfrm_state_check(x, skb);
+	if (err)
+		goto error;
+
+	xfrm6_encap(skb);
+
+	err = x->type->output(x, skb);
+	if (err)
+		goto error;
+
+	x->curlft.bytes += skb->len;
+	x->curlft.packets++;
+
+	spin_unlock_bh(&x->lock);
+
+	skb->nh.raw = skb->data;
+	
+	if (!(skb->dst = dst_pop(dst))) {
+		err = -EHOSTUNREACH;
+		goto error_nolock;
+	}
+	err = NET_XMIT_BYPASS;
+
+out_exit:
+	return err;
+error:
+	spin_unlock_bh(&x->lock);
+error_nolock:
+	kfree_skb(skb);
+	goto out_exit;
+}