1 files changed, 137 insertions, 0 deletions
diff --git a/net/ipv6/xfrm6_mode_beet.c b/net/ipv6/xfrm6_mode_beet.c
new file mode 100644
index 0000000..bbd48b1
--- /dev/null
+++ b/net/ipv6/xfrm6_mode_beet.c
@@ -0,0 +1,137 @@
+/*
+ * xfrm6_mode_beet.c - BEET mode encapsulation for IPv6.
+ *
+ * Copyright (c) 2006 Diego Beltrami <diego.beltrami@gmail.com>
+ *                    Miika Komu     <miika@iki.fi>
+ *                    Herbert Xu     <herbert@gondor.apana.org.au>
+ *                    Abhinav Pathak <abhinav.pathak@hiit.fi>
+ *                    Jeff Ahrenholz <ahrenholz@gmail.com>
+ */
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <linux/stringify.h>
+#include <net/dsfield.h>
+#include <net/dst.h>
+#include <net/inet_ecn.h>
+#include <net/ipv6.h>
+#include <net/xfrm.h>
+
+static void xfrm6_beet_make_header(struct sk_buff *skb)
+{
+	struct ipv6hdr *iph = ipv6_hdr(skb);
+
+	iph->version = 6;
+
+	memcpy(iph->flow_lbl, XFRM_MODE_SKB_CB(skb)->flow_lbl,
+	       sizeof(iph->flow_lbl));
+	iph->nexthdr = XFRM_MODE_SKB_CB(skb)->protocol;
+
+	ipv6_change_dsfield(iph, 0, XFRM_MODE_SKB_CB(skb)->tos);
+	iph->hop_limit = XFRM_MODE_SKB_CB(skb)->ttl;
+}
+
+/* Add encapsulation header.
+ *
+ * The top IP header will be constructed per draft-nikander-esp-beet-mode-06.txt.
+ */
+static int xfrm6_beet_output(struct xfrm_state *x, struct sk_buff *skb)
+{
+	struct ipv6hdr *top_iph;
+	struct ip_beet_phdr *ph;
+	struct iphdr *iphv4;
+	int optlen, hdr_len;
+
+	iphv4 = ip_hdr(skb);
+	hdr_len = 0;
+	optlen = XFRM_MODE_SKB_CB(skb)->optlen;
+	if (unlikely(optlen))
+		hdr_len += IPV4_BEET_PHMAXLEN - (optlen & 4);
+
+	skb_set_network_header(skb, -x->props.header_len - hdr_len);
+	if (x->sel.family != AF_INET6)
+		skb->network_header += IPV4_BEET_PHMAXLEN;
+	skb->mac_header = skb->network_header +
+			  offsetof(struct ipv6hdr, nexthdr);
+	skb->transport_header = skb->network_header + sizeof(*top_iph);
+	ph = (struct ip_beet_phdr *)__skb_pull(skb, XFRM_MODE_SKB_CB(skb)->ihl-hdr_len);
+
+	xfrm6_beet_make_header(skb);
+
+	top_iph = ipv6_hdr(skb);
+	if (unlikely(optlen)) {
+
+		BUG_ON(optlen < 0);
+
+		ph->padlen = 4 - (optlen & 4);
+		ph->hdrlen = optlen / 8;
+		ph->nexthdr = top_iph->nexthdr;
+		if (ph->padlen)
+			memset(ph + 1, IPOPT_NOP, ph->padlen);
+
+		top_iph->nexthdr = IPPROTO_BEETPH;
+	}
+
+	ipv6_addr_copy(&top_iph->saddr, (struct in6_addr *)&x->props.saddr);
+	ipv6_addr_copy(&top_iph->daddr, (struct in6_addr *)&x->id.daddr);
+	return 0;
+}
+
+static int xfrm6_beet_input(struct xfrm_state *x, struct sk_buff *skb)
+{
+	struct ipv6hdr *ip6h;
+	const unsigned char *old_mac;
+	int size = sizeof(struct ipv6hdr);
+	int err;
+
+	err = skb_cow_head(skb, size + skb->mac_len);
+	if (err)
+		goto out;
+
+	__skb_push(skb, size);
+	skb_reset_network_header(skb);
+
+	old_mac = skb_mac_header(skb);
+	skb_set_mac_header(skb, -skb->mac_len);
+	memmove(skb_mac_header(skb), old_mac, skb->mac_len);
+
+	xfrm6_beet_make_header(skb);
+
+	ip6h = ipv6_hdr(skb);
+	ip6h->payload_len = htons(skb->len - size);
+	ipv6_addr_copy(&ip6h->daddr, (struct in6_addr *) &x->sel.daddr.a6);
+	ipv6_addr_copy(&ip6h->saddr, (struct in6_addr *) &x->sel.saddr.a6);
+	err = 0;
+out:
+	return err;
+}
+
+static struct xfrm_mode xfrm6_beet_mode = {
+	.input2 = xfrm6_beet_input,
+	.input = xfrm_prepare_input,
+	.output2 = xfrm6_beet_output,
+	.output = xfrm6_prepare_output,
+	.owner = THIS_MODULE,
+	.encap = XFRM_MODE_BEET,
+	.flags = XFRM_MODE_FLAG_TUNNEL,
+};
+
+static int __init xfrm6_beet_init(void)
+{
+	return xfrm_register_mode(&xfrm6_beet_mode, AF_INET6);
+}
+
+static void __exit xfrm6_beet_exit(void)
+{
+	int err;
+
+	err = xfrm_unregister_mode(&xfrm6_beet_mode, AF_INET6);
+	BUG_ON(err);
+}
+
+module_init(xfrm6_beet_init);
+module_exit(xfrm6_beet_exit);
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_XFRM_MODE(AF_INET6, XFRM_MODE_BEET);