/* * 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> /* Add encapsulation header. * * The top IP header will be constructed per draft-nikander-esp-beet-mode-06.txt. * The following fields in it shall be filled in by x->type->output: * payload_len * * 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_beet_output(struct xfrm_state *x, struct sk_buff *skb) { struct ipv6hdr *iph, *top_iph; u8 *prevhdr; int hdr_len; skb_push(skb, x->props.header_len); iph = ipv6_hdr(skb); hdr_len = ip6_find_1stfragopt(skb, &prevhdr); skb_set_network_header(skb, (prevhdr - x->props.header_len) - skb->data); skb_set_transport_header(skb, hdr_len); memmove(skb->data, iph, hdr_len); skb_reset_network_header(skb); top_iph = ipv6_hdr(skb); skb->transport_header = skb->network_header + sizeof(struct ipv6hdr); skb->network_header += offsetof(struct ipv6hdr, nexthdr); 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 = -EINVAL; if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) goto out; skb_push(skb, size); memmove(skb->data, skb_network_header(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); 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 = { .input = xfrm6_beet_input, .output = xfrm6_beet_output, .owner = THIS_MODULE, .encap = XFRM_MODE_BEET, }; 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);