Commit 1ababeba authored by David Lebrun's avatar David Lebrun Committed by David S. Miller
Browse files

ipv6: implement dataplane support for rthdr type 4 (Segment Routing Header) 

Implement minimal support for processing of SR-enabled packets
as described in
https://tools.ietf.org/html/draft-ietf-6man-segment-routing-header-02

.

This patch implements the following operations:
- Intermediate segment endpoint: incrementation of active segment and rerouting.
- Egress for SR-encapsulated packets: decapsulation of outer IPv6 header + SRH
  and routing of inner packet.
- Cleanup flag support for SR-inlined packets: removal of SRH if we are the
  penultimate segment endpoint.

A per-interface sysctl seg6_enabled is provided, to accept/deny SR-enabled
packets. Default is deny.

This patch does not provide support for HMAC-signed packets.

Signed-off-by: default avatarDavid Lebrun <david.lebrun@uclouvain.be>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent dc0b2c9c

include/linux/ipv6.h

+1 −0
Original line number Diff line number Diff line
@@ -64,6 +64,7 @@ struct ipv6_devconf { 
	} stable_secret;

	__s32		use_oif_addrs_only;

	__s32		keep_addr_on_down;

	__s32		seg6_enabled;



	struct ctl_table_header *sysctl_header;

};

include/linux/seg6.h

0 → 100644
+6 −0
Original line number Diff line number Diff line 
#ifndef _LINUX_SEG6_H

#define _LINUX_SEG6_H



#include <uapi/linux/seg6.h>



#endif

include/net/seg6.h

0 → 100644
+36 −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 _NET_SEG6_H

#define _NET_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);

}



#endif

include/uapi/linux/ipv6.h

+2 −0
Original line number Diff line number Diff line
@@ -39,6 +39,7 @@ struct in6_ifreq { 
#define IPV6_SRCRT_STRICT	0x01	/* Deprecated; will be removed */

#define IPV6_SRCRT_TYPE_0	0	/* Deprecated; will be removed */

#define IPV6_SRCRT_TYPE_2	2	/* IPv6 type 2 Routing Header	*/

#define IPV6_SRCRT_TYPE_4	4	/* Segment Routing with IPv6 */



/*

 *	routing header
@@ -178,6 +179,7 @@ enum { 
	DEVCONF_DROP_UNSOLICITED_NA,

	DEVCONF_KEEP_ADDR_ON_DOWN,

	DEVCONF_RTR_SOLICIT_MAX_INTERVAL,

	DEVCONF_SEG6_ENABLED,

	DEVCONF_MAX

};

include/uapi/linux/seg6.h

0 → 100644
+54 −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_H

#define _UAPI_LINUX_SEG6_H



/*

 * SRH

 */

struct ipv6_sr_hdr {

	__u8	nexthdr;

	__u8	hdrlen;

	__u8	type;

	__u8	segments_left;

	__u8	first_segment;

	__u8	flag_1;

	__u8	flag_2;

	__u8	reserved;



	struct in6_addr segments[0];

};



#define SR6_FLAG1_CLEANUP	(1 << 7)

#define SR6_FLAG1_PROTECTED	(1 << 6)

#define SR6_FLAG1_OAM		(1 << 5)

#define SR6_FLAG1_ALERT		(1 << 4)

#define SR6_FLAG1_HMAC		(1 << 3)



#define SR6_TLV_INGRESS		1

#define SR6_TLV_EGRESS		2

#define SR6_TLV_OPAQUE		3

#define SR6_TLV_PADDING		4

#define SR6_TLV_HMAC		5



#define sr_has_cleanup(srh) ((srh)->flag_1 & SR6_FLAG1_CLEANUP)

#define sr_has_hmac(srh) ((srh)->flag_1 & SR6_FLAG1_HMAC)



struct sr6_tlv {

	__u8 type;

	__u8 len;

	__u8 data[0];

};



#endif

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