/* * 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> static void xfrm6_beet_make_header(struct sk_buff *skb) { struct ipv6hdr *iph = ipv6_hdr(skb); iph->version = 6; memcpy(iph->flow_lbl, XFRM_MODE_SKB_CB(skb)->flow_lbl, sizeof(iph->flow_lbl)); iph->nexthdr = XFRM_MODE_SKB_CB(skb)->protocol; ipv6_change_dsfield(iph, 0, XFRM_MODE_SKB_CB(skb)->tos); iph->hop_limit = XFRM_MODE_SKB_CB(skb)->ttl; } /* Add encapsulation header. * * The top IP header will be constructed per draft-nikander-esp-beet-mode-06.txt. */ static int xfrm6_beet_output(struct xfrm_state *x, struct sk_buff *skb) { struct ipv6hdr *top_iph; struct ip_beet_phdr *ph; int optlen, hdr_len; hdr_len = 0; optlen = XFRM_MODE_SKB_CB(skb)->optlen; if (unlikely(optlen)) hdr_len += IPV4_BEET_PHMAXLEN - (optlen & 4); skb_set_network_header(skb, -x->props.header_len - hdr_len); if (x->sel.family != AF_INET6) skb->network_header += IPV4_BEET_PHMAXLEN; skb->mac_header = skb->network_header + offsetof(struct ipv6hdr, nexthdr); skb->transport_header = skb->network_header + sizeof(*top_iph); ph = (struct ip_beet_phdr *)__skb_pull(skb, XFRM_MODE_SKB_CB(skb)->ihl-hdr_len); xfrm6_beet_make_header(skb); top_iph = ipv6_hdr(skb); if (unlikely(optlen)) { BUG_ON(optlen < 0); ph->padlen = 4 - (optlen & 4); ph->hdrlen = optlen / 8; ph->nexthdr = top_iph->nexthdr; if (ph->padlen) memset(ph + 1, IPOPT_NOP, ph->padlen); top_iph->nexthdr = IPPROTO_BEETPH; } top_iph->saddr = *(struct in6_addr *)&x->props.saddr; 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; int size = sizeof(struct ipv6hdr); int err; err = skb_cow_head(skb, size + skb->mac_len); if (err) goto out; __skb_push(skb, size); skb_reset_network_header(skb); skb_mac_header_rebuild(skb); xfrm6_beet_make_header(skb); ip6h = ipv6_hdr(skb); ip6h->payload_len = htons(skb->len - size); ip6h->daddr = *(struct in6_addr *)&x->sel.daddr.a6; ip6h->saddr = *(struct in6_addr *)&x->sel.saddr.a6; err = 0; out: return err; } static struct xfrm_mode xfrm6_beet_mode = { .input2 = xfrm6_beet_input, .input = xfrm_prepare_input, .output2 = xfrm6_beet_output, .output = xfrm6_prepare_output, .owner = THIS_MODULE, .encap = XFRM_MODE_BEET, .flags = XFRM_MODE_FLAG_TUNNEL, }; 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);