linux/include/net/seg6.h
David Lebrun 6c8702c60b ipv6: sr: add support for SRH encapsulation and injection with lwtunnels
This patch creates a new type of interfaceless lightweight tunnel (SEG6),
enabling the encapsulation and injection of SRH within locally emitted
packets and forwarded packets.

>From a configuration viewpoint, a seg6 tunnel would be configured as follows:

  ip -6 ro ad fc00::1/128 encap seg6 mode encap segs fc42::1,fc42::2,fc42::3 dev eth0

Any packet whose destination address is fc00::1 would thus be encapsulated
within an outer IPv6 header containing the SRH with three segments, and would
actually be routed to the first segment of the list. If `mode inline' was
specified instead of `mode encap', then the SRH would be directly inserted
after the IPv6 header without outer encapsulation.

The inline mode is only available if CONFIG_IPV6_SEG6_INLINE is enabled. This
feature was made configurable because direct header insertion may break
several mechanisms such as PMTUD or IPSec AH.

Signed-off-by: David Lebrun <david.lebrun@uclouvain.be>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-11-09 20:40:06 -05:00

58 lines
1.3 KiB
C

/*
* SR-IPv6 implementation
*
* Author:
* David Lebrun <david.lebrun@uclouvain.be>
*
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#ifndef _NET_SEG6_H
#define _NET_SEG6_H
#include <linux/net.h>
#include <linux/ipv6.h>
#include <net/lwtunnel.h>
#include <linux/seg6.h>
static inline void update_csum_diff4(struct sk_buff *skb, __be32 from,
__be32 to)
{
__be32 diff[] = { ~from, to };
skb->csum = ~csum_partial((char *)diff, sizeof(diff), ~skb->csum);
}
static inline void update_csum_diff16(struct sk_buff *skb, __be32 *from,
__be32 *to)
{
__be32 diff[] = {
~from[0], ~from[1], ~from[2], ~from[3],
to[0], to[1], to[2], to[3],
};
skb->csum = ~csum_partial((char *)diff, sizeof(diff), ~skb->csum);
}
struct seg6_pernet_data {
struct mutex lock;
struct in6_addr __rcu *tun_src;
};
static inline struct seg6_pernet_data *seg6_pernet(struct net *net)
{
return net->ipv6.seg6_data;
}
extern int seg6_init(void);
extern void seg6_exit(void);
extern int seg6_iptunnel_init(void);
extern void seg6_iptunnel_exit(void);
extern bool seg6_validate_srh(struct ipv6_sr_hdr *srh, int len);
#endif