diff options
Diffstat (limited to 'linux/net/ipv6/xfrm6_mode_transport.c')
-rw-r--r-- | linux/net/ipv6/xfrm6_mode_transport.c | 85 |
1 files changed, 85 insertions, 0 deletions
diff --git a/linux/net/ipv6/xfrm6_mode_transport.c b/linux/net/ipv6/xfrm6_mode_transport.c new file mode 100644 index 00000000..4e344105 --- /dev/null +++ b/linux/net/ipv6/xfrm6_mode_transport.c @@ -0,0 +1,85 @@ +/* + * 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. + */ +static int xfrm6_transport_output(struct xfrm_state *x, struct sk_buff *skb) +{ + struct ipv6hdr *iph; + u8 *prevhdr; + int hdr_len; + + iph = ipv6_hdr(skb); + + hdr_len = x->type->hdr_offset(x, skb, &prevhdr); + skb_set_mac_header(skb, (prevhdr - x->props.header_len) - skb->data); + skb_set_network_header(skb, -x->props.header_len); + skb->transport_header = skb->network_header + hdr_len; + __skb_pull(skb, hdr_len); + memmove(ipv6_hdr(skb), iph, hdr_len); + 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 xfrm6_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; + } + ipv6_hdr(skb)->payload_len = htons(skb->len + ihl - + sizeof(struct ipv6hdr)); + skb_reset_transport_header(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); |