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Commit 6c8702c6 authored by David Lebrun's avatar David Lebrun Committed by David S. Miller
Browse files

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: default avatarDavid Lebrun <david.lebrun@uclouvain.be>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 915d7e5e

include/linux/seg6_iptunnel.h

0 → 100644
+6 −0
Original line number Diff line number Diff line 
#ifndef _LINUX_SEG6_IPTUNNEL_H

#define _LINUX_SEG6_IPTUNNEL_H



#include <uapi/linux/seg6_iptunnel.h>



#endif

include/net/seg6.h

+6 −0
Original line number Diff line number Diff line
@@ -16,6 +16,8 @@ 


#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)
@@ -48,5 +50,9 @@ static inline struct seg6_pernet_data *seg6_pernet(struct net *net) 


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

include/uapi/linux/lwtunnel.h

+1 −0
Original line number Diff line number Diff line
@@ -9,6 +9,7 @@ enum lwtunnel_encap_types { 
	LWTUNNEL_ENCAP_IP,

	LWTUNNEL_ENCAP_ILA,

	LWTUNNEL_ENCAP_IP6,

	LWTUNNEL_ENCAP_SEG6,

	__LWTUNNEL_ENCAP_MAX,

};

include/uapi/linux/seg6_iptunnel.h

0 → 100644
+44 −0
Original line number Diff line number Diff line 
/*

 *  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 _UAPI_LINUX_SEG6_IPTUNNEL_H

#define _UAPI_LINUX_SEG6_IPTUNNEL_H



enum {

	SEG6_IPTUNNEL_UNSPEC,

	SEG6_IPTUNNEL_SRH,

	__SEG6_IPTUNNEL_MAX,

};

#define SEG6_IPTUNNEL_MAX (__SEG6_IPTUNNEL_MAX - 1)



struct seg6_iptunnel_encap {

	int mode;

	struct ipv6_sr_hdr srh[0];

};



#define SEG6_IPTUN_ENCAP_SIZE(x) ((sizeof(*x)) + (((x)->srh->hdrlen + 1) << 3))



enum {

	SEG6_IPTUN_MODE_INLINE,

	SEG6_IPTUN_MODE_ENCAP,

};



static inline size_t seg6_lwt_headroom(struct seg6_iptunnel_encap *tuninfo)

{

	int encap = (tuninfo->mode == SEG6_IPTUN_MODE_ENCAP);



	return ((tuninfo->srh->hdrlen + 1) << 3) +

	       (encap * sizeof(struct ipv6hdr));

}



#endif

net/core/lwtunnel.c

+2 −0
Original line number Diff line number Diff line
@@ -39,6 +39,8 @@ static const char *lwtunnel_encap_str(enum lwtunnel_encap_types encap_type) 
		return "MPLS";

	case LWTUNNEL_ENCAP_ILA:

		return "ILA";

	case LWTUNNEL_ENCAP_SEG6:

		return "SEG6";

	case LWTUNNEL_ENCAP_IP6:

	case LWTUNNEL_ENCAP_IP:

	case LWTUNNEL_ENCAP_NONE: