Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / net / ipv4 / xfrm4_mode_transport.c

diff --git a/kernel/net/ipv4/xfrm4_mode_transport.c b/kernel/net/ipv4/xfrm4_mode_transport.c
new file mode 100644 (file)
index 0000000..fd840c7
--- /dev/null
+++ b/kernel/net/ipv4/xfrm4_mode_transport.c
@@ -0,0 +1,80 @@
+/*
+ * xfrm4_mode_transport.c - Transport mode encapsulation for IPv4.
+ *
+ * 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/ip.h>
+#include <net/xfrm.h>
+
+/* Add encapsulation header.
+ *
+ * The IP header will be moved forward to make space for the encapsulation
+ * header.
+ */
+static int xfrm4_transport_output(struct xfrm_state *x, struct sk_buff *skb)
+{
+       struct iphdr *iph = ip_hdr(skb);
+       int ihl = iph->ihl * 4;
+
+       skb_set_network_header(skb, -x->props.header_len);
+       skb->mac_header = skb->network_header +
+                         offsetof(struct iphdr, protocol);
+       skb->transport_header = skb->network_header + ihl;
+       __skb_pull(skb, ihl);
+       memmove(skb_network_header(skb), iph, ihl);
+       return 0;
+}
+
+/* Remove encapsulation header.
+ *
+ * The IP header will be moved over the top of the encapsulation header.
+ *
+ * On entry, skb->h shall point to where the IP header should be and skb->nh
+ * shall be set to where the IP header currently is.  skb->data shall point
+ * to the start of the payload.
+ */
+static int xfrm4_transport_input(struct xfrm_state *x, struct sk_buff *skb)
+{
+       int ihl = skb->data - skb_transport_header(skb);
+
+       if (skb->transport_header != skb->network_header) {
+               memmove(skb_transport_header(skb),
+                       skb_network_header(skb), ihl);
+               skb->network_header = skb->transport_header;
+       }
+       ip_hdr(skb)->tot_len = htons(skb->len + ihl);
+       skb_reset_transport_header(skb);
+       return 0;
+}
+
+static struct xfrm_mode xfrm4_transport_mode = {
+       .input = xfrm4_transport_input,
+       .output = xfrm4_transport_output,
+       .owner = THIS_MODULE,
+       .encap = XFRM_MODE_TRANSPORT,
+};
+
+static int __init xfrm4_transport_init(void)
+{
+       return xfrm_register_mode(&xfrm4_transport_mode, AF_INET);
+}
+
+static void __exit xfrm4_transport_exit(void)
+{
+       int err;
+
+       err = xfrm_unregister_mode(&xfrm4_transport_mode, AF_INET);
+       BUG_ON(err);
+}
+
+module_init(xfrm4_transport_init);
+module_exit(xfrm4_transport_exit);
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_XFRM_MODE(AF_INET, XFRM_MODE_TRANSPORT);