| /* |
| * xfrm6_mode_tunnel.c - Tunnel mode encapsulation for IPv6. |
| * |
| * Copyright (C) 2002 USAGI/WIDE Project |
| * Copyright (c) 2004-2006 Herbert Xu <herbert@gondor.apana.org.au> |
| */ |
| |
| #include <linux/gfp.h> |
| #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/ip6_route.h> |
| #include <net/ipv6.h> |
| #include <net/xfrm.h> |
| |
| static inline void ipip6_ecn_decapsulate(struct sk_buff *skb) |
| { |
| const struct ipv6hdr *outer_iph = ipv6_hdr(skb); |
| struct ipv6hdr *inner_iph = ipipv6_hdr(skb); |
| |
| if (INET_ECN_is_ce(ipv6_get_dsfield(outer_iph))) |
| IP6_ECN_set_ce(inner_iph); |
| } |
| |
| /* Add encapsulation header. |
| * |
| * The top IP header will be constructed per RFC 2401. |
| */ |
| static int xfrm6_mode_tunnel_output(struct xfrm_state *x, struct sk_buff *skb) |
| { |
| struct dst_entry *dst = skb_dst(skb); |
| struct ipv6hdr *top_iph; |
| int dsfield; |
| |
| skb_set_network_header(skb, -x->props.header_len); |
| skb->mac_header = skb->network_header + |
| offsetof(struct ipv6hdr, nexthdr); |
| skb->transport_header = skb->network_header + sizeof(*top_iph); |
| top_iph = ipv6_hdr(skb); |
| |
| top_iph->version = 6; |
| |
| memcpy(top_iph->flow_lbl, XFRM_MODE_SKB_CB(skb)->flow_lbl, |
| sizeof(top_iph->flow_lbl)); |
| top_iph->nexthdr = xfrm_af2proto(skb_dst(skb)->ops->family); |
| |
| if (x->props.extra_flags & XFRM_SA_XFLAG_DONT_ENCAP_DSCP) |
| dsfield = 0; |
| else |
| dsfield = XFRM_MODE_SKB_CB(skb)->tos; |
| dsfield = INET_ECN_encapsulate(dsfield, XFRM_MODE_SKB_CB(skb)->tos); |
| if (x->props.flags & XFRM_STATE_NOECN) |
| dsfield &= ~INET_ECN_MASK; |
| ipv6_change_dsfield(top_iph, 0, dsfield); |
| top_iph->hop_limit = ip6_dst_hoplimit(dst->child); |
| top_iph->saddr = *(struct in6_addr *)&x->props.saddr; |
| top_iph->daddr = *(struct in6_addr *)&x->id.daddr; |
| return 0; |
| } |
| |
| #define for_each_input_rcu(head, handler) \ |
| for (handler = rcu_dereference(head); \ |
| handler != NULL; \ |
| handler = rcu_dereference(handler->next)) |
| |
| |
| static int xfrm6_mode_tunnel_input(struct xfrm_state *x, struct sk_buff *skb) |
| { |
| int err = -EINVAL; |
| |
| if (XFRM_MODE_SKB_CB(skb)->protocol != IPPROTO_IPV6) |
| goto out; |
| if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) |
| goto out; |
| |
| err = skb_unclone(skb, GFP_ATOMIC); |
| if (err) |
| goto out; |
| |
| if (x->props.flags & XFRM_STATE_DECAP_DSCP) |
| ipv6_copy_dscp(ipv6_get_dsfield(ipv6_hdr(skb)), |
| ipipv6_hdr(skb)); |
| if (!(x->props.flags & XFRM_STATE_NOECN)) |
| ipip6_ecn_decapsulate(skb); |
| |
| skb_reset_network_header(skb); |
| skb_mac_header_rebuild(skb); |
| |
| err = 0; |
| |
| out: |
| return err; |
| } |
| |
| static struct xfrm_mode xfrm6_tunnel_mode = { |
| .input2 = xfrm6_mode_tunnel_input, |
| .input = xfrm_prepare_input, |
| .output2 = xfrm6_mode_tunnel_output, |
| .output = xfrm6_prepare_output, |
| .owner = THIS_MODULE, |
| .encap = XFRM_MODE_TUNNEL, |
| .flags = XFRM_MODE_FLAG_TUNNEL, |
| }; |
| |
| static int __init xfrm6_mode_tunnel_init(void) |
| { |
| return xfrm_register_mode(&xfrm6_tunnel_mode, AF_INET6); |
| } |
| |
| static void __exit xfrm6_mode_tunnel_exit(void) |
| { |
| int err; |
| |
| err = xfrm_unregister_mode(&xfrm6_tunnel_mode, AF_INET6); |
| BUG_ON(err); |
| } |
| |
| module_init(xfrm6_mode_tunnel_init); |
| module_exit(xfrm6_mode_tunnel_exit); |
| MODULE_LICENSE("GPL"); |
| MODULE_ALIAS_XFRM_MODE(AF_INET6, XFRM_MODE_TUNNEL); |