From b59f45d0b2878ab76f8053b0973654e6621828ee Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Sat, 27 May 2006 23:05:54 -0700 Subject: [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 Signed-off-by: David S. Miller --- net/ipv4/xfrm4_mode_transport.c | 69 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 69 insertions(+) create mode 100644 net/ipv4/xfrm4_mode_transport.c (limited to 'net/ipv4/xfrm4_mode_transport.c') diff --git a/net/ipv4/xfrm4_mode_transport.c b/net/ipv4/xfrm4_mode_transport.c new file mode 100644 index 000000000000..e46d9a4ccc55 --- /dev/null +++ b/net/ipv4/xfrm4_mode_transport.c @@ -0,0 +1,69 @@ +/* + * xfrm4_mode_transport.c - Transport mode encapsulation for IPv4. + * + * Copyright (c) 2004-2006 Herbert Xu + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +/* Add encapsulation header. + * + * The IP header will be moved forward to make space for the encapsulation + * header. + * + * On exit, skb->h will be set to the start of the payload to be processed + * by x->type->output and skb->nh will be set to the top IP header. + */ +static int xfrm4_transport_output(struct sk_buff *skb) +{ + struct xfrm_state *x; + struct iphdr *iph; + int ihl; + + iph = skb->nh.iph; + skb->h.ipiph = iph; + + ihl = iph->ihl * 4; + skb->h.raw += ihl; + + x = skb->dst->xfrm; + skb->nh.raw = memmove(skb_push(skb, x->props.header_len), iph, ihl); + return 0; +} + +static int xfrm4_transport_input(struct xfrm_state *x, struct sk_buff *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); -- cgit v1.2.3-59-g8ed1b