| /* |
| * 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->nh.raw = prevhdr - x->props.header_len; |
| skb_set_transport_header(skb, hdr_len); |
| memmove(skb->data, iph, hdr_len); |
| |
| skb_reset_network_header(skb); |
| top_iph = ipv6_hdr(skb); |
| skb->h.raw = skb->nh.raw + sizeof(struct ipv6hdr); |
| skb->nh.raw += 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); |