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authorHerbert Xu <herbert@gondor.apana.org.au>2006-05-27 23:05:54 -0700
committerDavid S. Miller <davem@sunset.davemloft.net>2006-06-17 21:28:39 -0700
commitb59f45d0b2878ab76f8053b0973654e6621828ee (patch)
tree40dc5e2ede2620f7935fb3dae0d0eb199851f611 /net/ipv6/xfrm6_mode_transport.c
parent[IPSEC] xfrm: Undo afinfo lock proliferation (diff)
downloadlinux-dev-b59f45d0b2878ab76f8053b0973654e6621828ee.tar.xz
linux-dev-b59f45d0b2878ab76f8053b0973654e6621828ee.zip
[IPSEC] xfrm: Abstract out encapsulation modes
This patch adds the structure xfrm_mode. It is meant to represent the operations carried out by transport/tunnel modes. By doing this we allow additional encapsulation modes to be added without clogging up the xfrm_input/xfrm_output paths. Candidate modes include 4-to-6 tunnel mode, 6-to-4 tunnel mode, and BEET modes. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv6/xfrm6_mode_transport.c')
-rw-r--r--net/ipv6/xfrm6_mode_transport.c73
1 files changed, 73 insertions, 0 deletions
diff --git a/net/ipv6/xfrm6_mode_transport.c b/net/ipv6/xfrm6_mode_transport.c
new file mode 100644
index 000000000000..5efbbae08ef0
--- /dev/null
+++ b/net/ipv6/xfrm6_mode_transport.c
@@ -0,0 +1,73 @@
+/*
+ * xfrm6_mode_transport.c - Transport mode encapsulation for IPv6.
+ *
+ * Copyright (C) 2002 USAGI/WIDE Project
+ * Copyright (c) 2004-2006 Herbert Xu <herbert@gondor.apana.org.au>
+ */
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <linux/stringify.h>
+#include <net/dst.h>
+#include <net/ipv6.h>
+#include <net/xfrm.h>
+
+/* Add encapsulation header.
+ *
+ * The IP header and mutable extension headers will be moved forward to make
+ * space for the encapsulation header.
+ *
+ * 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 int xfrm6_transport_output(struct sk_buff *skb)
+{
+ struct xfrm_state *x = skb->dst->xfrm;
+ struct ipv6hdr *iph;
+ u8 *prevhdr;
+ int hdr_len;
+
+ skb_push(skb, x->props.header_len);
+ iph = skb->nh.ipv6h;
+
+ 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 0;
+}
+
+static int xfrm6_transport_input(struct xfrm_state *x, struct sk_buff *skb)
+{
+ return 0;
+}
+
+static struct xfrm_mode xfrm6_transport_mode = {
+ .input = xfrm6_transport_input,
+ .output = xfrm6_transport_output,
+ .owner = THIS_MODULE,
+ .encap = XFRM_MODE_TRANSPORT,
+};
+
+static int __init xfrm6_transport_init(void)
+{
+ return xfrm_register_mode(&xfrm6_transport_mode, AF_INET6);
+}
+
+static void __exit xfrm6_transport_exit(void)
+{
+ int err;
+
+ err = xfrm_unregister_mode(&xfrm6_transport_mode, AF_INET6);
+ BUG_ON(err);
+}
+
+module_init(xfrm6_transport_init);
+module_exit(xfrm6_transport_exit);
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_XFRM_MODE(AF_INET6, XFRM_MODE_TRANSPORT);