diff options
Diffstat (limited to 'net/ipv6/xfrm6_mode_tunnel.c')
| -rw-r--r-- | net/ipv6/xfrm6_mode_tunnel.c | 121 |
1 files changed, 121 insertions, 0 deletions
diff --git a/net/ipv6/xfrm6_mode_tunnel.c b/net/ipv6/xfrm6_mode_tunnel.c new file mode 100644 index 000000000000..8af79be2edca --- /dev/null +++ b/net/ipv6/xfrm6_mode_tunnel.c @@ -0,0 +1,121 @@ +/* + * 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/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 inline void ipip6_ecn_decapsulate(struct sk_buff *skb) +{ + struct ipv6hdr *outer_iph = skb->nh.ipv6h; + struct ipv6hdr *inner_iph = skb->h.ipv6h; + + 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. 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_tunnel_output(struct sk_buff *skb) +{ + struct dst_entry *dst = skb->dst; + struct xfrm_state *x = dst->xfrm; + struct ipv6hdr *iph, *top_iph; + int dsfield; + + skb_push(skb, x->props.header_len); + iph = skb->nh.ipv6h; + + skb->nh.raw = skb->data; + top_iph = skb->nh.ipv6h; + skb->nh.raw = &top_iph->nexthdr; + skb->h.ipv6h = top_iph + 1; + + top_iph->version = 6; + top_iph->priority = iph->priority; + top_iph->flow_lbl[0] = iph->flow_lbl[0]; + top_iph->flow_lbl[1] = iph->flow_lbl[1]; + top_iph->flow_lbl[2] = iph->flow_lbl[2]; + dsfield = ipv6_get_dsfield(top_iph); + dsfield = INET_ECN_encapsulate(dsfield, dsfield); + if (x->props.flags & XFRM_STATE_NOECN) + dsfield &= ~INET_ECN_MASK; + ipv6_change_dsfield(top_iph, 0, dsfield); + top_iph->nexthdr = IPPROTO_IPV6; + top_iph->hop_limit = dst_metric(dst->child, RTAX_HOPLIMIT); + 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_tunnel_input(struct xfrm_state *x, struct sk_buff *skb) +{ + int err = -EINVAL; + + if (skb->nh.raw[IP6CB(skb)->nhoff] != IPPROTO_IPV6) + goto out; + if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) + goto out; + + if (skb_cloned(skb) && + (err = pskb_expand_head(skb, 0, 0, GFP_ATOMIC))) + goto out; + + if (x->props.flags & XFRM_STATE_DECAP_DSCP) + ipv6_copy_dscp(skb->nh.ipv6h, skb->h.ipv6h); + if (!(x->props.flags & XFRM_STATE_NOECN)) + ipip6_ecn_decapsulate(skb); + skb->mac.raw = memmove(skb->data - skb->mac_len, + skb->mac.raw, skb->mac_len); + skb->nh.raw = skb->data; + err = 0; + +out: + return err; +} + +static struct xfrm_mode xfrm6_tunnel_mode = { + .input = xfrm6_tunnel_input, + .output = xfrm6_tunnel_output, + .owner = THIS_MODULE, + .encap = XFRM_MODE_TUNNEL, +}; + +static int __init xfrm6_tunnel_init(void) +{ + return xfrm_register_mode(&xfrm6_tunnel_mode, AF_INET6); +} + +static void __exit xfrm6_tunnel_exit(void) +{ + int err; + + err = xfrm_unregister_mode(&xfrm6_tunnel_mode, AF_INET6); + BUG_ON(err); +} + +module_init(xfrm6_tunnel_init); +module_exit(xfrm6_tunnel_exit); +MODULE_LICENSE("GPL"); +MODULE_ALIAS_XFRM_MODE(AF_INET6, XFRM_MODE_TUNNEL); |